@article{farias_rodrigues_botelho_magalhaes_raisanen_freeman_umbuzeiro_2024, title={The natural anthraquinone dye emodin: Eco/genotoxicological characterization for aquatic organisms}, volume={189}, ISSN={["1873-6351"]}, DOI={10.1016/j.fct.2024.114749}, abstractNote={Emodin is an anthraquinone secondary metabolite produced by several species of plants and fungi. Emodin is known for its pharmacological versatility, and, in the textile industry, for its good dyeing properties. However, its use in the textile industry can result in the formation and disposal of large volumes of wastewater. Emodin mutagenicity has been shown in bacteria and in human cells, but little is known about its possible toxic, genotoxic, or mutagenic effects in aquatic organisms. We have evaluated the eco/genotoxicity of emodin to aquatic organisms. Emodin was toxic to Daphnia similis (EC}, journal={FOOD AND CHEMICAL TOXICOLOGY}, author={Farias, Natalia Oliveira and Rodrigues, Amanda Rocha and Botelho, Marina Tenorio and Magalhaes, Gabriel Rampazzo and Raisanen, Riikka and Freeman, Harold S. and Umbuzeiro, Gisela de Aragao}, year={2024}, month={Jul} }
 @article{magalhaes_militao_farias_albuquerque_botelho_raisanen_freeman_aragao umbuzeiro_2023, title={Acryloyl esters of emodin for waterless dyeing and toxicological studies}, ISSN={["1478-4408"]}, DOI={10.1111/cote.12731}, abstractNote={Abstract}, journal={COLORATION TECHNOLOGY}, author={Magalhaes, Gabriel Rampazzo and Militao, Gabriely Fernanda Groto and Farias, Natalia Oliveira and Albuquerque, Anjaina Fernandes and Botelho, Marina Tenorio and Raisanen, Riikka and Freeman, Harold S. and Aragao Umbuzeiro, Gisela}, year={2023}, month={Oct} }
 @article{otaviano_sannomiya_lima_tangerina_tamayose_ferreira_freeman_flor_costa_costa_2023, title={Pomegranate peel extract and zinc oxide as a source of natural dye and functional material for textile fibers aiming for photoprotective properties}, volume={293}, ISSN={["1879-3312"]}, DOI={10.1016/j.matchemphys.2022.126766}, abstractNote={The use of photoprotection products is indispensable today, due to the potential harmful effects of ultraviolet (UV) rays. Textiles are a natural barrier against UV radiation and can be made more effective by applying UV blockers. The present study investigates the photoprotection properties arising from dyeing cotton fabric with pomegranate peel extract. The extract was characterized by TPC, TFC, THT, color, pH, HPLC-UV and including its antiradical activity. The dyed fabric samples were evaluated for color, color fastness to light, rubbing, washing and sweating, along with a determination of SEM, EDS, ATR-FTIR, and UPF properties. The chemical analyses of the P. granatum peel aqueous extract by HPLC-UV indicated the presence of ellagic acid, punicalagin and punicalin derivatives. The extract showed antiradical activity (11.1 ± 0.4 CI50 (mg L−1) which is consistent with a high amount of total phenols 307 ± 26 (mg GAE/g extract), total flavonoids 150.3 ± 2.3 (mg RE/g extract), and condensed tannins 632.6 ± 84.1 (mg TAE/g extract). The dyed fabric samples showed yellowish colors and good color fastness ratings. The evaluation of the Ultraviolet Protection Factor (UPF) indicated mostly values from 15 to 24, equivalent to the category of good to very good photoprotection. Bearing in mind that ZnO is often used in combination with other UV-blockers to enhance the coverage of sunscreens, an aspect of this study involved determining the UPF of the pomegranate extract mixed with ZnO. In this case, ZnO addition did not significantly enhance the UPF of the dyed cotton fabric.}, journal={MATERIALS CHEMISTRY AND PHYSICS}, author={Otaviano, Bryna Tieme Haraki and Sannomiya, Miriam and Lima, Fernando Soares and Tangerina, Marcelo Marucci Pereira and Tamayose, Cinthia Indy and Ferreira, Marcelo Jose Pena and Freeman, Harold S. and Flor, Juliana Pereira and Costa, Silgia Aparecida da and Costa, Sirlene Maria}, year={2023}, month={Jan} }
 @article{silva_franca_queiroz_lima_freeman_costa_costa_2022, title={Copaifera langsdorffii Desf. bark extract: optimisation of dyeing conditions to wool and colour fastness properties}, volume={36}, ISSN={["1478-6427"]}, DOI={10.1080/14786419.2021.1872567}, abstractNote={Abstract The ability to add value to waste materials from industrial operations has come to the attention of the wood processing industry, with reports, for example, of extracts from the bark tree conveying colour and UV protection to textile fibres. The objective of the present work was to expand our developments in this arena by using Copaifera langsdorffii Desf. bark extract as a natural dye for textile dyeing. A complete 2³-statistical experimental design and the central point was elaborated. The results showed that the optimal dyeing conditions were 98 °C, for 60 min, using undiluted bark extract. The dyed fabric was analysed by a spectrophotometer using the CIELAB system for evaluation of the colour strength. The results showed a K/S value of 5.78, and the dyed fabric had good colour fastness to rubbing and washing. Graphical Abstract}, number={14}, journal={NATURAL PRODUCT RESEARCH}, author={Silva, Patricia Muniz dos Santos and Franca, Vitoria Hamawaki and Queiroz, Rayana Santiago de and Lima, Fernando Soares de and Freeman, Harold S. and Costa, Silgia Aparecida da and Costa, Sirlene Maria da}, year={2022}, month={Jul}, pages={3744–3749} }
 @article{williams_vacchi_santos_szymczyk_umbuzeiro_freeman_2022, title={Evaluation of the Toxicological and Color Properties of Anionic Hydrophobic Monoazo Dyes for Sustainable Human Hair Coloration}, volume={10}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.1c05702}, DOI={10.1021/acssuschemeng.1c05702}, abstractNote={The design of hair dyes having environmentally benign characteristics in addition to very good durability to washing and UV light is of importance to overcome the limitations of conventional permanent hair dyes in the marketplace. As a step toward meeting this vision, we synthesized anionic azo dyes having a built-in C4, C8, or C12 alkyl chain and evaluated their hair dyeing and toxicological properties. As anticipated, the dyes increased in hydrophobicity (SlogP) with the increase in alkyl chain length. Based on prior technology, it is known that certain anionic textile dyes possessing a C12 group exhibit high affinity for wool fibers during rigorous washing in the commercial milling process. In the present study, the dye containing the C8 chain displayed the greatest uptake and the most promise as a potential permanent hair dye. Further, dyes containing a C4 or C8 carbon chain were found to be nontoxic ≤100 mg L using the crustaceans Daphnia similis and Parhyale hawaiensis as test organisms. The dye containing a C12 carbon chain provided an EC50 of 57.4 mg L–1 using D. similis, but it was nontoxic ≤100 mg L–1 to P. hawaiensis. All dyes were nontoxic using the algae Raphidocelis subcapitata, and none of the dyes exhibited mutagenicity toward the strains used.}, number={8}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, author={Williams, Tova N. and Vacchi, Francine I. and Santos, Amanda and Szymczyk, Malgorzata and Umbuzeiro, Gisela de Aragao and Freeman, Harold S.}, year={2022}, month={Feb}, pages={2593–2601} }
 @article{silva_sanchez_ibarra-rodriguez_freeman_2022, title={Isomeric tetrazole-based organic dyes for dye-sensitized solar cells: Structure-property relationships}, volume={1250}, ISSN={["1872-8014"]}, DOI={10.1016/j.molstruc.2021.131749}, abstractNote={Two new organic dyes (SD-1 and SD-2) featured with donor–π–acceptor architecture were synthesized and applied to dye-sensitized solar cells (DSSCs). In these sensitizers, an azo bridge π-spacer is used to link the phenyl tetrazole acceptor with 2-naphthol donors. To amplify the pull-push effect, the nitro group was connected to the electron acceptor group. The effect of the position of the nitro group and the tetrazole group linked to the benzene ring on the photophysical, electrochemical, and photovoltaic properties of sensitizers are investigated in detail. They all show intense UV–Vis absorptions around 400 nm and 510 nm. The co-sensitizations of SD-1 and SD-2 with ruthenium complex HD-2 are further evaluated and the co-sensitization results were compared with DCA. Co-sensitization of HD-2 with SD-2 was more efficient than found for co-sensitization with DCA (5.6% higher). Moreover, the influences of molecular geometry on charge recombination and photovoltaic performance of DSSCs were systematically investigated by incident photon to current efficiency (IPCE) spectra and electrochemical impedance spectroscopy (EIS) investigations.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Silva, Luciano and Sanchez, Mario and Ibarra-Rodriguez, Marisol and Freeman, Harold S.}, year={2022}, month={Feb} }
 @article{williams_vacchi_santos_aragaumbuzeiro_freeman_2022, title={Metal-complexed monoazo dyes as sustainable permanent hair dye alternatives-Toxicological and durability properties}, volume={197}, ISSN={["1873-3743"]}, url={https://doi.org/10.1016/j.dyepig.2021.109819}, DOI={10.1016/j.dyepig.2021.109819}, abstractNote={As a new approach to permanent/oxidative hair dyes, we demonstrated that certain monoazo dyes containing substituents that enable diffusion into hair fibers and subsequent chelation/complexation using benign metal ions (Al3+ and Fe3+), rather than a harsh oxidant and strong alkali, merit consideration in this application area. This is important, because billions of individuals worldwide color their hair using permanent hair dye products that can contain aromatic amines and phenols that display genotoxicity and/or skin sensitization (e.g., para-phenylenediamine, PPD). Herein, our work is extended to an examination of the toxicological properties and durability of metallizable monoazo dyes, in comparison to a commercially used permanent hair dye product. Results from the Salmonella/microsome mutagenicity assay and from acute toxicity tests using aquatic test organisms (Daphnia similis, 48-h and Parhyale hawaiensis, 96-h) indicated that the proposed dyes were significantly less toxic than the top-eight permanent hair dye precursors utilized annually. Regarding durability, monoazo dye chelation in situ led to a higher degree of resistance to removal by washing than a commercial permanent hair dye. Taken together, these results further demonstrate the potential of the dyes as sustainable alternatives to conventional permanent hair dyes.}, journal={DYES AND PIGMENTS}, publisher={Elsevier BV}, author={Williams, Tova N. and Vacchi, Francine I. and Santos, Amanda and AragaUmbuzeiro, Gisela and Freeman, Harold S.}, year={2022}, month={Jan} }
 @article{ding_szymczyk_mehraban_lim_parrillo-chapman_el-shafei_freeman_2022, title={Molecular and excited state properties of photostable anthraquinone red and violet dyes for hydrophobic fibers}, volume={1248}, ISSN={["1872-8014"]}, DOI={10.1016/j.molstruc.2021.131349}, abstractNote={The molecular, spectroscopic, and excited state properties of synthetic dyes for fiber-based outdoor materials continue to be of commercial interest. Early developments in this area were reported in the 1980s, when the need for dyes for polyester (PET)-based automobile interiors gave rise to commercially viable nitrodiphenylamine yellow, anthraquinone red and blue, and azo red dyes. To augment that initial knowledge base, the present study involved the use of experimental and theoretical methods to help establish the molecular structures and excited state properties of some more recent dyes for producing photostable colors on PET fibers. Having completed the characterization of present-day scarlet, blue, and yellow disperse dyes for PET-based fibers used outdoors, our attention turned to commercially available red and violet dyes. In this regard, HPLC analysis showed that the red product was a mixture containing four components, while the violet product contained only one component. Results from 1H NMR, HRMS, and single crystal X-ray diffraction analyses indicated that the principal components were dyes having a 1-amino-4-hydroxyanthraquinone base structure. The presence of an –OH group alpha to an anthraquinone C=O moiety provides for intramolecular H-bonding and a subsequent opportunity for intramolecular proton transfer in the excited state – as a photostabilizing mechanism. Further, for both dyes, results from the analysis of Frontier HOMO and LUMO isosurfaces indicated strong HOMO-LUMO overlap without molecular gaps and were consistent with strong excited state energy dissipation in a non-destructive way.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Ding, Yi and Szymczyk, Malgorzata and Mehraban, Nahid and Lim, Jihye and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2022}, month={Jan} }
 @article{aragao umbuzeiro_freeman_raisanen_2022, title={Mutagenicity of dyes: a call to fill the knowledge gaps and improve our predictive ability}, volume={368}, ISSN={["1879-3169"]}, DOI={10.1016/j.toxlet.2022.07.217}, journal={TOXICOLOGY LETTERS}, author={Aragao Umbuzeiro, G. and Freeman, H. S. and Raisanen, R.}, year={2022}, month={Sep}, pages={S73–S73} }
 @article{herrala_yli-oyra_albuquerque_farias_morales_raisanen_freeman_umbuzeiro_rysa_2022, title={Waterless Dyeing and In Vitro Toxicological Properties of Biocolorants from Cortinarius sanguineus}, volume={8}, ISSN={["2309-608X"]}, DOI={10.3390/jof8111129}, abstractNote={As a part of an ongoing interest in identifying environmentally friendly alternatives to synthetic dyes and in using liquid CO2 as a waterless medium for applying the resulting colorants to textiles, our attention turned to yellow-to-red biocolorants produced by Cortinarius sanguineus fungus. The three principal target anthraquinone colorants (emodin, dermocybin, and dermorubin) were isolated from the fungal bodies using a liquid–liquid separation method and characterized using 700 MHz NMR and high-resolution mass spectral analyses. Following structure confirmations, the three colorants were examined for dyeing synthetic polyester (PET) textile fibers in supercritical CO2. We found that all three biocolorants were suitable for dyeing PET fibers using this technology, and our attention then turned to determining their toxicological properties. As emodin has shown mutagenic potential in previous studies, we concentrated our present toxicity studies on dermocybin and dermorubin. Both colorants were non-mutagenic, presented low cellular toxicity, and did not induce skin sensitization. Taken together, our results indicate that dermocybin and dermorubin possess the technical and toxicological properties needed for consideration as synthetic dye alternatives under conditions that are free of wastewater production.}, number={11}, journal={JOURNAL OF FUNGI}, author={Herrala, Mikko and Yli-oyra, Johanna and Albuquerque, Anjaina Fernandes and Farias, Natalia Oliveira and Morales, Daniel Alexandre and Raisanen, Riikka and Freeman, Harold S. and Umbuzeiro, Gisela Aragao and Rysa, Jaana}, year={2022}, month={Nov} }
 @article{raisanen_montero_freeman_2021, title={A fungal-based anthraquinone emodin for polylactide and polyethylene terephthalate in supercritical carbon dioxide (SC-CO2) dyeing}, volume={46}, ISSN={["1520-6378"]}, DOI={10.1002/col.22627}, abstractNote={Abstract}, number={3}, journal={COLOR RESEARCH AND APPLICATION}, author={Raisanen, Riikka and Montero, Gerardo A. and Freeman, Harold S.}, year={2021}, month={Jun}, pages={674–680} }
 @article{umbuzeiro_morales_vacchi_albuquerque_szymczyk_sui_vinueza_freeman_2021, title={A promising Ames battery for mutagenicity characterization of new dyes}, volume={62}, ISSN={["1098-2280"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85097440491&partnerID=MN8TOARS}, DOI={10.1002/em.22417}, abstractNote={Abstract}, number={1}, journal={ENVIRONMENTAL AND MOLECULAR MUTAGENESIS}, author={Umbuzeiro, Gisela A. and Morales, Daniel A. and Vacchi, Francine I and Albuquerque, Anjaina F. and Szymczyk, Malgorzata and Sui, Xinyi and Vinueza, Nelson and Freeman, Harold S.}, year={2021}, month={Jan}, pages={52–65} }
 @article{kim_danilov_yoon_el-shafei_freeman_2021, title={Characterization of the photophysics of a mixed system of red disperse dyes using experimental and theoretical methods}, volume={184}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85090416933&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2020.108745}, abstractNote={While many disperse dyes have been studied in a variety of scientific fields, from textiles to biochemistry, most studies have been conducted on individual dyes having specific chromogens. However, bearing in mind that dyes are often used in combinations, in order to produce target colors for outdoor environments, an understanding of the photophysics of mixed system of dyes is important. As an extension of our previous work pertaining to scarlet and blue disperse dyes developed for use in outdoor applications, we investigated the photophysics of two commercial colorants and their various components (azo and anthraquinone red disperse dyes) to help account for their photostability when used in combinations. In this regard, experimental and modeling studies were performed to get insight into excited-state properties following light absorption. Transient absorption spectroscopy (TAS) showed that the dye mixtures dissipated excited-state energy much faster than the main component (an anthraquinone disperse red dye), which emphasized the benefit of multiple components in a commercial dye. The reduced excited-state lifetime clearly showed that the presence of additional dyes can play an important role in the photophysics and improving photostability.}, journal={DYES AND PIGMENTS}, author={Kim, Bo Hyung and Danilov, Evgeny and Yoon, Seog Joon and El-Shafei, Ahmed and Freeman, Harold}, year={2021}, month={Jan} }
 @article{williams_szymczyk_freeman_2021, title={In situ Chelation of Monoazo Dyes in Human Hair Keratin Fibers Using Environmentally Benign Metal Ions}, volume={4}, url={https://doi.org/10.1021/acsabm.1c00512}, DOI={10.1021/acsabm.1c00512}, abstractNote={The coloration of human hair keratin fibers has long involved the oxidative coupling of primarily aromatic amines and phenols inside the fibers with the aid of harsh agents such as H2O2 and NH4OH. Further, the traditional process has exposed millions of consumers and their hairstylists to toxic substances such as skin sensitizers. While alternative hair dyeing processes have been explored, they fail to be competitive with the traditional method, for reasons including impracticality and limited colors achievable. In the present study, we developed an approach to imparting color to human hair fibers that involves entrapping colorants inside hair fibers by forming chelated monoazo dyes in situ. Dyes employed were based on monoarylide, arylazopyrazolone, and arylazonaphthol families, which display yellow, orange, and magenta colors on dyed hair. The dyes were applied at 40 °C without the use of oxidants and alkali associated with current commercial hair dyes, with the best dye uptake observed when the arylazonaphthol dye was employed. The dyed hair fibers showed good durability to washing, and treatment of these fibers with Al3+ or Fe3+ ions at 40 °C led to the rapid in situ formation of 1:2 metal/dye structures. In addition, the dyed hair was soft, indicating that chelated dye occupies the interior of the fibers rather than the surface. Such an approach can be applied to the coloration of other materials, including textiles.}, number={8}, journal={ACS Applied Bio Materials}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Szymczyk, Malgorzata and Freeman, Harold S.}, year={2021}, month={Aug}, pages={6195–6202} }
 @article{freeman_santos_chen_vendemiatti_oliveira_vacchi_vinueza_umbuzeiro_2021, title={Molecular characterization and ecotoxicological evaluation of the natural dye madder and its chlorinated products}, volume={11}, ISSN={["1614-7499"]}, DOI={10.1007/s11356-021-17388-4}, abstractNote={There has been increased interest in the use of natural dyes for textile coloration as alternatives to synthetic dyes, due to the general belief that natural dyes are more environmentally friendly. However, natural dyes have poor affinity for textiles, which can lead to high dye levels in the resultant wastewater. While chlorine treatment has proven to be effective for dye wastewater disinfection and decolorization, this process can also lead to the formation of more toxic degradation products for certain synthetic dyes. On the other hand, little information is available regarding the ecotoxicity of natural dyes and their chlorination products. To advance knowledge in this area, madder was selected due to its historical importance and wide application in the textile industry. Specifically, we sought to characterize the chlorine-induced degradation products of an aqueous madder solution and to assess their ecotoxicity. The main component of the present madder sample was Alizarin (89.8%). Chlorination led to complete decolorization, and 2-hydroxynaphthalene-1,4-dione and phthalic anhydride were identified as key degradation products. Chlorination of madder decreased toxicity to Daphnia similis (microcrustacean) 10-fold and removed the toxicity to Raphidocellis subcapitata (algae), when compared to the parent dye.}, journal={ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH}, author={Freeman, Harold S. and Santos, Tuane C. and Chen, Yufei and Vendemiatti, Josiane A. S. and Oliveira, Adria C. and Vacchi, Francine I. and Vinueza, Nelson R. and Umbuzeiro, Gisela A.}, year={2021}, month={Nov} }
 @article{hipolito bezerra_fiaschitello_labuto_freeman_fragoso_costa_costa_2021, title={Reuse of water from real reactive monochromic and trichromic wastewater for new cotton dyes after efficient treatment using H2O2 catalyzed by UV light}, volume={9}, ISSN={["2213-3437"]}, DOI={10.1016/j.jece.2021.105731}, abstractNote={The textile industry widely uses reactive dyes to obtain cotton fabrics having good resistance to color removal despite frequent washing. This level of dye usage generates substantial volumes of wastewater containing significant quantities of residual dye requiring treatment before discharges from commercial dyeing operations to public waterways. As part of a study aimed at recycling/reusing rather than discharging reactive dye wastewater, well-known dyes Reactive Yellow 176, Reactive Red 241, and Reactive Blue 221 were used in dyeing cotton fabric, and the generated wastewater samples were decolorized with H2O2 catalyzed by UV light. The efficiency of UV/H2O2 decolorization for trichromic wastewater was determined by UV-Vis monitoring at 550 nm, wherein it was found that more than 91% of color removal in trichromic wastewater occurred at pH 4. The reuse of wastewater was investigated by a total of three sequential cycles of wastewater treatments. The quality of cotton dyed with reused wastewater was assessed through color measurements using CIELAB, fastness to light, and wash fastness testing. Results showed that MCT/VS-based reactive dye wastewater arising from UV/ H2O2 treatment could be used for two subsequent dyeing cycles without compromising the quality of the color of the dyed cotton fabrics. The proposed treatment can also save water and salt, enhancing the economy of the dyeing process.}, number={4}, journal={JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING}, author={Hipolito Bezerra, Katia Crystina and Fiaschitello, Ticiane Rossi and Labuto, Georgia and Freeman, Harold S. and Fragoso, Wallace Duarte and Costa, Sirlene Maria and Costa, Silgia Aparecida}, year={2021}, month={Aug} }
 @article{arangdad_yildirim_detwiler_cleven_burk_shamey_pasquinelli_freeman_el-shafei_2021, title={X-ray photoelectron spectroscopy study on the photodegradation of copolyester model compounds}, volume={138}, ISSN={["1097-4628"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85088566956&partnerID=MN8TOARS}, DOI={10.1002/app.49661}, abstractNote={Abstract}, number={2}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Arangdad, Kiarash and Yildirim, Erol and Detwiler, Andrew and Cleven, Curtis D. and Burk, Christopher and Shamey, Renzo and Pasquinelli, Melissa A. and Freeman, Harold and El-Shafei, Ahmed}, year={2021}, month={Jan} }
 @article{ding_szymczyk_mehraban_lim_parrillo-chapman_el-shafei_freeman_2020, title={Molecular and excited state properties of photostable yellow disperse dyes}, volume={1207}, ISSN={["1872-8014"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85078970244&partnerID=MN8TOARS}, DOI={10.1016/j.molstruc.2020.127815}, abstractNote={Textile dyes with high resistance to UV light induced fading on poly (ethylene terephthalate) (PET) fibers are important for textile substrates used in applications such as automobile interiors and outdoor furniture. Dye photostability influenced the development of dye structures for automobile fabrics dating back to the 1980s but the nature of currently used disperse dyes is less widely known. As part of a study designed to provide updates on this subject, the current investigation employed experimental and theoretical methods to determine the nature and properties of commercial dyes used to produce lightfast colors on PET fibers. Having completed the characterization of scarlet and blue disperse dyes for PET-based fabrics used outdoors, our attention turned to the characterization of commercially available lightfast yellow dyes. HPLC analysis showed that a pair of yellow products were mixtures containing three or four dyes, and the use of 1NMR, HRMS and single crystal X-ray diffraction analyses indicated that they were homologous azo–anthraquinone based dyes with or without a 1,8-bis(phenylthio)anthraquinone dye. Results from calculating Frontier HOMO and LUMO isosurfaces indicated strong HOMO/LUMO overlap, and the E0-0 for the homologous anthraquinone-based azo dyes was exactly the same (2.37 eV) which contributes to their photostability.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Ding, Yi and Szymczyk, Malgorzata and Mehraban, Nahid and Lim, Jihye and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2020}, month={May} }
 @article{santos silva_fiaschitello_queiroz_freeman_costa_leo_montemor_costa_2020, title={Natural dye from Croton urucurana Baill. bark: Extraction, physicochemical characterization, textile dyeing and color fastness properties}, volume={173}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2019.107953}, abstractNote={Natural dyes have become an alternative option of interest for textile dyeing. The selection of native species as a natural dye can make its use feasible and enhance local biodiversity. In the present study, the extract of Croton urucurana Baill. bark, which is native to Brazil, was investigated as a natural textile dye. The extract showed a reddish-brown color and the presence of tannins. The extract was characterized by physicochemical methods and optimization of the dyeing process was determined by factorial design 23. The dyed fabrics were evaluated for color fastness to light, wash, rubbing and perspiration. They showed colors between beige and reddish-brown and had good fastness properties. Antibacterial activity assessment was performed on the extract and fabrics and UV protection was evaluated in the fabrics. The wastewater generated from the dyeing process was also characterized. It exhibited high biochemical oxygen demand and chemical oxygen demand, in addition to a large amount of dissolved iron and aluminum, when these metals were used as a mordant in the dyeing process. On balance, the extract of C. urucurana has the potential to be employed as a textile dye.}, journal={DYES AND PIGMENTS}, author={Santos Silva, Patricia Muniz and Fiaschitello, Ticiane Rossi and Queiroz, Rayana Santiago and Freeman, Harold S. and Costa, Silgia Aparecida and Leo, Patricia and Montemor, Antonio Fernando and Costa, Sirlene Maria}, year={2020}, month={Feb} }
 @article{silva_sanchez_freeman_2020, title={New tetrazole based dyes as efficient co-sensitizers for dsscs: Structure-properties relationship}, volume={87}, ISSN={["1878-5530"]}, DOI={10.1016/j.orgel.2020.105964}, abstractNote={Two new compounds based on the phenyltetrazole system, 5-(4-decyloxyphenyl)tetrazole (LTz-4) and N,N-diethyl-4-{[(2′-nitro-4′-tetrazoyl)phenyl]diazenyl}aniline (SD - 6), were synthesized and characterized as co-adsorbents in Dye-Sensitized Solar Cells (DSSCs). The effects of hydrophobic chain length and anchoring group on the properties of DSSCs containing the previously reported dye HD-14 and compared with the benchmark deoxycholic acid (DCA) are described. The charge-transfer resistance of dye/TiO2 interface followed the order HD-14 – SD - 6 > HD-14 – LTz-4 > HD-14 –DCA. However, the VOC for the dye HD-14 with co-adsorbent DCA was 0.71 V, for the and the dye HD-14 with co-adsorbent LTz-4 was 0.70 V and for the dye HD-14 with co-adsorbent SD - 6 was 0.67 V. Co-adsorbents LTz-4 and SD - 6 achieved mean solar-to-power conversion efficiencies (%η), for three devices, of 9.20 and 7.48, respectively, compared to 9.14 for DCA under the same experimental device conditions. For LTz-4 co-adsorbent, the results can be attributed to the repellent effect of the long alkyl chain that prevents the charge recombination on the semiconductor surface. For SD - 6, the molecular volume of the co-adsorbent and the presence of the nitro group in a lateral position should make it difficult to form a more compact layer with the dye. The sum of these contributions would allow the electrolyte to approach, reducing the efficiency of electron injection into TiO2.}, journal={ORGANIC ELECTRONICS}, author={Silva, Luciano and Sanchez, Mario and Freeman, Harold S.}, year={2020}, month={Dec} }
 @article{fei_freeman_hinks_2020, title={Toward closed loop recycling of polyester fabric: Step 1. decolorization using sodium formaldehyde sulfoxylate}, volume={254}, ISBN={1879-1786}, DOI={10.1016/j.jclepro.2020.120027}, abstractNote={Although polyethylene terephthalate (PET) fibers comprise the largest single fiber type used in the global textile community, recycling of dyed PET-based fabric is limited, resulting in the disposal of considerable amounts of PET fabric in landfills every year. Because PET does not readily biodegrade, interest in recycling some or all of the dyed textiles derived from this substrate is of interest. A step toward achieving this vision was investigated in this study, namely the development of an effective decolorization process. In this study, sodium formaldehyde sulfoxylate (SFS) was employed to decolorize disperse dyes developed for PET and it was found effective for decolorizing C.I. Disperse Yellow 42, C.I. Disperse Orange 30, and C.I. Disperse Blue 56 in water/acetone media and the process was extended to the decolorization of dyed PET fabric. An optimized combination of treatment time (30 min), water to acetone ratio (1:2), SFS concentration (10 g/L), temperature (100 °C), and liquor ratio (50/1) was found to give good color removal for a range of well-known and widely used disperse dye types. Fabric strength assessments were also investigated and it was found that SFS decolorization had no influence on PET strength, as judged by intrinsic viscosity and bursting strength measurements. It was also found that the acetone component of the decolorization medium could be recovered and reused.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Fei, Xiuzhu and Freeman, Harold S. and Hinks, David}, year={2020} }
 @article{williams_freeman_2019, title={Analysis of keratin films as screening tools for predicting the efficacy of potential hair dyes}, volume={135}, ISSN={["1478-4408"]}, url={https://doi.org/10.1111/cote.12408}, DOI={10.1111/cote.12408}, abstractNote={Abstract}, number={4}, journal={COLORATION TECHNOLOGY}, publisher={Wiley}, author={Williams, Tova N. and Freeman, Harold S.}, year={2019}, month={Aug}, pages={253–266} }
 @article{zaidy_vacchi_umbuzeiro_freeman_2019, title={Approach to Waterless Dyeing of Textile Substrates-Use of Atmospheric Plasma}, volume={58}, ISSN={["0888-5885"]}, DOI={10.1021/acs.iecr.9b01260}, abstractNote={The international textile wet processing industry produces large amounts of wastewater, which if discharged into the environment could have adverse effects on aquatic life and drinking water. Effor...}, number={40}, journal={INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH}, author={Zaidy, Syed S. H. and Vacchi, Francine I. and Umbuzeiro, Gisela A. and Freeman, Harold S.}, year={2019}, month={Oct}, pages={18478–18487} }
 @article{arangdad_yildirim_detwiler_cleven_burk_shamey_pasquinelli_freeman_el-shafei_2019, title={Influence of UV stabilizers on the weathering of PETG and PCTT films}, volume={136}, ISSN={["1097-4628"]}, url={https://doi.org/10.1002/app.48198}, DOI={10.1002/app.48198}, abstractNote={ABSTRACT}, number={47}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, publisher={Wiley}, author={Arangdad, Kiarash and Yildirim, Erol and Detwiler, Andrew and Cleven, Curtis D. and Burk, Christopher and Shamey, Renzo and Pasquinelli, Melissa A. and Freeman, Harold S. and El-Shafei, Ahmed}, year={2019}, month={Dec} }
 @article{ding_mehraban_szymczyk_parrillo-chapman_el-shafei_freeman_2019, title={Molecular and excited state properties of photostable anthraquinone blue dyes for hydrophobic fibers}, volume={1181}, ISSN={0022-2860}, url={http://dx.doi.org/10.1016/J.MOLSTRUC.2018.12.070}, DOI={10.1016/j.molstruc.2018.12.070}, abstractNote={Abstract Synthetic dyes having high photostability on hydrophobic fibers such as poly(ethylene terephthalate) (PET) are of interest for use on textile substrates for outdoor applications. While much is known about photostable dyes developed for PET in the 1980s, owing to their viability for use in automobile interiors, little has been published on currently viable photostable disperse dyes. As part of an effort to help fill this void and to facilitate future photostable disperse dye design, the present study involved the use of experimental measurements and modelling studies to help characterize the molecular structures of commercially viable dyes for producing photostable colors on PET fibers, beginning with a pair of blue dyes. With the aid of HR-MS, 500 MHz 1H NMR, and X-ray crystallography, it was established that the two dyes are structural isomers having 1,5-(OH)2-anthraquinone (AQ) and 1,8-(OH)2-AQ base structures. It is proposed that the photostability of these dyes arises from the presence of multiple OH/NH groups ortho to the AQ C O groups which enables them to dissipate excited state energy through intramolecular proton transfer. Further, using DFT-based molecular modelling studies, it was shown that the dye having the 1,5-(OH)2-AQ base structure has a lower ESOP than the isomeric dye having the 1,8-(OH)2-AQ base structure. Similarly, results from calculating Frontier HOMO and LUMO isosurfaces indicated that the LUMO lobes of the latter dye are larger, suggesting that this dye undergoes excitation faster than the 1,5-(OH)2-AQ isomer.}, journal={Journal of Molecular Structure}, publisher={Elsevier BV}, author={Ding, Yi and Mehraban, Nahid and Szymczyk, Malgorzata and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2019}, month={Apr}, pages={109–117} }
 @article{ding_shamey_chapman_freeman_2019, title={Pretreatment effects on pigment-based textile inkjet printing - colour gamut and crockfastness properties}, volume={135}, ISSN={["1478-4408"]}, url={https://doi.org/10.1111/cote.12377}, DOI={10.1111/cote.12377}, abstractNote={The application of two commercial pretreatment agents, formulated to improve the performance of a six‐colour nano‐scale pigment ink set during the textile inkjet printing of cotton and polyester (PET) fabrics, was examined. An industrial scale printer, operating at 55 linear m/h and equipped with Kyocera printheads, was used to print on commercial fabrics (180 cm wide) prepared for digital printing. The work employed an industrial scale rather than a benchtop printer to enhance the utility of the results for a commercial environment. The colorimetric attributes of printed fabrics were recorded for the individual inks as well as for spot colour combinations generated using Dr. Wirth RIPMaster v11 software. Colour table profiles were also generated and the colorimetric values of inks were compared. Colour gamuts of inks on cotton and PET, including three‐dimensional volumes in the CIELab space, were examined to assess the role of pretreatment on the colorimetric properties of the printed substrates. It was found that the pretreatments enhanced the ink receptiveness, colour intensity and colour gamut of fabrics. Pretreatment of cotton resulted in a larger gamut and more vivid colours than on PET. However, wet and dry crockfastness results were found to be low. In this regard, Time‐of‐Flight Secondary Ion Mass Spectrometry analysis of fabrics printed in the presence and absence of pretreatment indicated that the low crockfastness arises from higher pigment levels on the surface of the pretreated fabric.}, number={1}, journal={COLORATION TECHNOLOGY}, publisher={Wiley}, author={Ding, Yi and Shamey, Renzo and Chapman, Lisa Parillo and Freeman, Harold S.}, year={2019}, month={Feb}, pages={77–86} }
 @article{mehraban_musich_freeman_2019, title={Synthesis and Encapsulation of a New Zinc Phthalocyanine Photosensitizer into Polymeric Nanoparticles to Enhance Cell Uptake and Phototoxicity}, volume={9}, ISSN={["2076-3417"]}, DOI={10.3390/app9030401}, abstractNote={Efforts to enhance the utility of photodynamic therapy as a non-invasive method for treating certain cancers have often involved the design of dye sensitizers with increased singlet oxygen efficiency. More recently, however, sensitizers with greater selectivity for tumor cells than surrounding tissue have been targeted. The present study provides an approach to the modification of the known photosensitizer zinc phthalocyanine (ZnPc), to enhance its solubility and delivery to cancer cells. Targeting a photosensitizer to the site of action improves the efficacy of the sensitizer in photodynamic therapy. In this work we used PLGA-b-PEG to encapsulate a new zinc phthalocyanine derivative, 2(3), 9(10), 16(17), 23(24)-tetrakis-(4’-methyl-benzyloxy) phthalocyanine zinc(II) (ZnPcBCH3), to enhance uptake into A549 cells, a human lung cancer cell line. ZnPcBCH3 exhibited the same photochemical properties as the parent compound ZnPc but gave increased solubility in organic solvents, which allowed for efficient encapsulation. In addition, the encapsulated dye showed a near 500-fold increase in phototoxicity for A549 cancer cells compared to free dye.}, number={3}, journal={APPLIED SCIENCES-BASEL}, author={Mehraban, Nahid and Musich, Phillip R. and Freeman, Harold S.}, year={2019}, month={Feb} }
 @article{umbuzeiro_albuquerque_vacchi_szymczyk_sui_aalizadeh_ohe_thomaidis_vinueza_freeman_2019, title={Towards a reliable prediction of the aquatic toxicity of dyes}, volume={31}, ISSN={["2190-4715"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85074502142&partnerID=MN8TOARS}, DOI={10.1186/s12302-019-0258-1}, abstractNote={Abstract}, number={1}, journal={ENVIRONMENTAL SCIENCES EUROPE}, author={Umbuzeiro, Gisela de A. and Albuquerque, Anjaina F. and Vacchi, Francine I and Szymczyk, Malgorzata and Sui, Xinyi and Aalizadeh, Reza and Ohe, Peter C. and Thomaidis, Nikolaos S. and Vinueza, Nelson R. and Freeman, Harold S.}, year={2019}, month={Dec} }
 @article{silva_freeman_2019, title={Variation in hydrophobic chain length of co-adsorbents to improve dye-sensitized solar cell performance}, volume={21}, ISSN={["1463-9084"]}, DOI={10.1039/c9cp02439e}, abstractNote={Improving the performance of dye-sensitized solar cells with the right choice of the molecular structure of the co-adsorbents.}, number={30}, journal={PHYSICAL CHEMISTRY CHEMICAL PHYSICS}, author={Silva, Luciano and Freeman, Harold}, year={2019}, month={Aug}, pages={16771–16778} }
 @article{ding_parrillo-chapman_freeman_2018, title={A study of the effects of fabric pretreatment on color gamut from inkjet printing on polyester}, volume={109}, ISSN={["1754-2340"]}, DOI={10.1080/00405000.2017.1415623}, abstractNote={Abstract This paper pertains to characterizing the effects of a commercial pretreatment agent formulated specifically for digital printing on polyester (PET) fabric using pigment-based inks. Emphasis was placed on evaluating the colorimetric attributes of individual and mixed inks, from color patches generated using Dr Wirth RIPMaster V11 software and on developing an approach to addressing color-bleeding problems that can occur from inkjet printing on PET. In addition, 3-D color gamut analysis was undertaken using Origin software. Results indicated that the pretreatment increased color intensity, improved print quality and enlarged the color gamut. In another set of experiments, the use of different ink limits indicated no obvious change of color gamut using the same print mode, which afforded an opportunity to reduce ink consumption, thus the cost in large-scale production, and minimize color bleeding. To aid the potential commercial utility of the outcomes of this investigation, an industrial scale inkjet printer (MS JP5 evo) was used.}, number={9}, journal={JOURNAL OF THE TEXTILE INSTITUTE}, author={Ding, Yi and Parrillo-Chapman, Lisa and Freeman, Harold S.}, year={2018}, pages={1143–1151} }
 @article{lim_szymczyk_mehraban_ding_parrillo-chapman_el-shafei_freeman_2018, title={Data from X-ray crystallographic analysis and DFT calculations on isomeric azo disperse dyes}, volume={21}, ISSN={["2352-3409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85055317185&partnerID=MN8TOARS}, DOI={10.1016/j.dib.2018.10.010}, abstractNote={X-ray crystallography and DFT calculations were used to characterize the molecular nature and excited state properties of isomeric photostable azo dyes for textile fibers undergoing extensive sunlight exposure. Structural data in CIF files arising from X-ray analysis are reported and the complete files are deposited with the Cambridge Crystallographic Data Centre as CCDC 1548989 (https://www.ccdc.cam.ac.uk/structures/Search?Ccdcid=1548989) and CCDC 1548990 (https://www.ccdc.cam.ac.uk/structures/Search?Ccdcid=1548990). Data from calculating the vertical electronic excitation of 20 excited states for each dye and from calculating excited state oxidation potential (ESOP) and Frontier HOMO/LUMO isosurfaces are also presented. This data is related to the article “Molecular and excited state properties of isomeric scarlet disperse dyes” (Lim et al., 2018) [1].}, journal={DATA IN BRIEF}, author={Lim, Jihye and Szymczyk, Malgorzata and Mehraban, Nahid and Ding, Yi and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2018}, month={Dec}, pages={675–683} }
 @article{ding_parrillo-chapman_freeman_2018, title={Developing the methodology of colour gamut analysis and print quality evaluation for textile ink-jet printing: Delphi method}, volume={134}, ISSN={["1478-4408"]}, DOI={10.1111/cote.12319}, abstractNote={This research used the Delphi method to investigate current colour gamut analysis methods, which is a critical component of colour management systems (CMS). Thirteen ink‐jet printing experts were interviewed to understand how they manage colour and their process for analysing and comparing colour gamut. A significant result of this study was the development of a four‐stage process model for colour gamut analysis and print quality evaluation for textile ink‐jet printing. The optimal process model was verified and approved by experts. This study uncovered an industry initiative toward the improvement of CMS for more accurate colour matching, a need to stabilise variables in the manufacturing process, and a need to standardise related tests and evaluations. The study also revealed new CMS software and technologies developed for ink formulation and pre‐/post‐treatment methods to facilitate high quality production in textile ink‐jet printing.}, number={2}, journal={COLORATION TECHNOLOGY}, author={Ding, Yi and Parrillo-Chapman, Lisa and Freeman, Harold S.}, year={2018}, month={Apr}, pages={135–147} }
 @article{sultana_liu_szymczyk_freeman_vinueza_2018, title={Dimerised heterobifunctional reactive dyes. Part 1: characterisation using quadrupole time-of-flight mass spectrometry}, volume={134}, ISSN={1472-3581}, url={http://dx.doi.org/10.1111/cote.12368}, DOI={10.1111/cote.12368}, abstractNote={As part of an approach to enhancing the efficiency of reactive dye adsorption on cellulosic fibres at low electrolyte levels, commercially available dyes were dimerised using hexamethylenediamine (HMDA) as a linking group. A key component of this work involved using high‐resolution mass spectrometry (HRMS) to characterise a group of polysulphonated heterobifunctional monochlorotriazine/vinyl sulphone reactive dyes (CI Reactive Yellow 176, CI Reactive Red 239, CI Reactive Blue 221, CI Reactive Red 194 and CI Reactive Blue 222) and their dimeric analogs. In this respect, dimeric dye ions of differently charged states were observed using HRMS‐negative electrospray ionisation in combination with quadrupole time‐of‐flight mass spectrometry. For example, HRMS showed that the HMDA‐linked reaction products were mixtures of the target (unhydrolysed) dimers, hydrolysed dimers, monoreacted products and hydrolysed unreacted dyes, with CI Reactive Yellow 176 and CI Reactive Red 194 producing the desired unhydrolysed dimers.}, number={6}, journal={Coloration Technology}, publisher={Wiley}, author={Sultana, Nadia and Liu, Yixin and Szymczyk, Malgorzata and Freeman, Harold S. and Vinueza, Nelson R.}, year={2018}, month={Aug}, pages={470–477} }
 @article{lim_szymczyk_mehraban_ding_parrillo-chapman_el-shafei_freeman_2018, title={Molecular and excited state properties of isomeric scarlet disperse dyes}, volume={1161}, ISSN={["1872-8014"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85042332047&partnerID=MN8TOARS}, DOI={10.1016/j.molstruc.2018.02.028}, abstractNote={This work was part of an investigation aimed at characterizing the molecular and excited state properties of currently available disperse dyes developed to provide stability to extensive sunlight exposures when adsorbed on poly(ethylene terephthalate) (PET) fibers. Having completed the characterization of yellow, magenta, and cyan disperse dyes for PET-based fabrics used outdoors, our attention turned to the colors designed to enhance the color gamut of a standard 4-member (cyan/yellow/magenta/black) color set. The present study pertained specifically to the characterization of commercially available scarlet dyes. In this regard, HPLC analysis showed that a scarlet product used for PET coloration was mainly a 70/30 mixture of dyes, and the use of HRMS and single crystal X-ray diffraction analyses indicated that these two dyes were azo compounds derived from isomeric pyridine-based couplers which differed in the location of the primary amino (NH2) and anilino (NHPh) groups attached to the pyridine ring. One dye structure has the NHPh group para to the azo group (Sc2), while the other has that group in the ortho position (Sc3). The presence of either ortho substituent provides photostabilization through intramolecular H-bonding with the azo moiety. Further, results from molecular modeling studies showed that the lower excited state oxidation potential of Sc3 relative to that of Sc2 allows Sc3 to function as an energy quencher for the excited state of Sc2 – through thermodynamically favorable electron transfer.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Lim, Jihye and Szymczyk, Malgorzata and Mehraban, Nahid and Ding, Yi and Parrillo-Chapman, Lisa and El-Shafei, Ahmed and Freeman, Harold S.}, year={2018}, month={Jun}, pages={254–261} }
 @article{williams_kuenemann_driessche_williams_fourches_freeman_2018, title={Toward the Rational Design of Sustainable Hair Dyes Using Cheminformatics Approaches: Step 1. Database Development and Analysis}, volume={6}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.7b03795}, DOI={10.1021/acssuschemeng.7b03795}, abstractNote={Herein, we report on the initial step of the design process of new hair dyes with the desired properties. The first step is dedicated to the development of the largest, publicly available database of hair dye substances (containing temporary and semipermanent hair dyes as well as permanent hair dye precursors) used in commercial hair dye formulations. The database was utilized to perform a cheminformatics study assessing the computed physicochemical properties of the different hair dye substances, especially within each cluster of structurally similar dyes. The various substances could be differentiated based on their average molecular weight, hydrophobicity, topological polar surface area, and number of hydrogen bond acceptors, with some overlap also observed. In particular, we found that dyes such as C.I. Basic Orange 1 and 2 were clustered among the precursors, suggesting that their diffusion behavior is similar to that of permanent hair dye precursors. We anticipate taking advantage of this interestin...}, number={2}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Kuenemann, Melaine A. and Driessche, George A. and Williams, Antony J. and Fourches, Denis and Freeman, Harold S.}, year={2018}, month={Feb}, pages={2344–2352} }
 @article{williams_driessche_valery_fourches_freeman_2018, title={Toward the Rational Design of Sustainable Hair Dyes Using Cheminformatics Approaches: Step 2. Identification of Hair Dye Substance Database Analogs in the Max Weaver Dye Library}, volume={6}, ISSN={["2168-0485"]}, url={https://doi.org/10.1021/acssuschemeng.8b02882}, DOI={10.1021/acssuschemeng.8b02882}, abstractNote={We report on part 2 of the cheminformatics-assisted development of sustainable hair dyes with enhanced technical and toxicological properties. In this study, an initial similarity search analysis was performed using two reference probes (C.I. Basic Orange 1 and Orange 2) as structural templates for the identification of potential analogs among the Max Weaver Dye Library (MWDL). The analysis revealed an interesting subset of 158 MWDL compounds that were close analogs of the classical aminoazobenzene dyes. A more detailed similarity search analysis of this subset ultimately led to the selection of four dyes for further in silico quantum calculations and experimental dye uptake (color depth on hair) studies. Results from quantum calculations indicated that the ESP surface properties of these dyes were consistent with nonionic interactions between dye and keratin. Among the four dye analogs, 2-amino-6-methyl-5-(phenyldiazenyl)pyrimidin-4-ol and 2-amino-4-chloro-1,6-dimethyl-5-(phenyldiazenyl)-pyrimidin-1-ium ...}, number={11}, journal={ACS SUSTAINABLE CHEMISTRY & ENGINEERING}, publisher={American Chemical Society (ACS)}, author={Williams, Tova N. and Driessche, George A. and Valery, Alain R. B. and Fourches, Denis and Freeman, Harold S.}, year={2018}, month={Nov}, pages={14248–14256} }
 @article{ding_freeman_parrillo-chapman_2017, title={Color Gamut Analysis and Color Fastness Evaluation for Textile Inkjet Printing Application on Polyester}, volume={61}, ISSN={["1943-3522"]}, DOI={10.2352/j.imagingsci.technol.2017.61.5.050503}, abstractNote={As part of a study aimed at selecting inksets for printing fabrics for outdoor use, pigment-based and disperse dye-based inksets were evaluated on polyester fabric via textile inkjet printing. Colorimetric attributes were recorded for each color, as well as the mixed colors generated through RIPMaster V11 software. Color Table (CTB) profiles were created to compare spot colors and International color consortium (ICC) profiles were created to evaluate color gamut volumes. Four-color and seven-color disperse dye-based inksets were evaluated, along with six-color and eight-color pigment-based inksets . Four-color and seven-color combination of disperse and pigment inksets were compared. As expected, the addition of colors to the basic four-color inkset increased the color gamuts significantly. It was also found that the disperse dye-based inkset provided deeper colors, and excellent wet and dry crock fastness. However, light fastness from the disperse dye-based inksets was not as high as the levels obtained using pigment-based inksets.}, number={5}, journal={JOURNAL OF IMAGING SCIENCE AND TECHNOLOGY}, author={Ding, Yi and Freeman, Harold S. and Parrillo-Chapman, Lisa}, year={2017}, month={Sep} }
 @article{ding_freeman_2017, title={Mordant dye application on cotton: optimisation and combination with natural dyes}, volume={133}, ISSN={["1478-4408"]}, DOI={10.1111/cote.12288}, abstractNote={It is well known that cotton fibres can be dyed through the formation of coordinate bonds involving cellulose chains, mordants such as alum, and natural dyes such as alizarin. Similarly, synthetic dyes known as mordant acid dyes can be used to dye wool fibres. Unlike mordant dyes on wool, the fastnesses of natural dyes on cotton are often low. Although concerns surrounding textile sustainability have sparked renewed interest in the use of natural dyes, extensive replacement of synthetic dyes with natural dyes is neither practical nor fundamentally possible. However, similarities in dyeing methods using mordant and natural dyes raise the possibility of using mordant dyes as alternatives to natural dyes in the dyeing of cotton. Further, the potential for combining suitable dyes from these two classes to expand the colour gamut currently available from natural dyes on cotton seem worthy of exploration. The results of this study indicate that shades comparable with those produced by natural dyes can be obtained on cotton using select mordant dyes following Fe2+ and Al3+ pretreatments. The best results were obtained using a two‐step/two‐bath process and dyes such as CI Mordant Blue 13 and CI Mordant Orange 6. In evaluations of mordant and natural dye combinations using the two mordant dyes logwood and Osage orange as prototypes, interesting fabric shades were obtained. However, the fastness properties of these dyes must be improved in order to produce commercially viable dyeings.}, number={5}, journal={COLORATION TECHNOLOGY}, author={Ding, Yi and Freeman, Harold S.}, year={2017}, month={Oct}, pages={369–375} }
 @article{rossi_silva_de moura_araujo_brito_freeman_2017, title={Waste from eucalyptus wood steaming as a natural dye source for textile fibers}, volume={143}, ISSN={["1879-1786"]}, DOI={10.1016/j.jclepro.2016.12.109}, abstractNote={Natural dyes are gaining interest due their expected low risk to human health and the environment and biodegradability. In addition, there are ever-growing potential new sources of natural dyes in the form of production waste products that merit consideration for coloration of materials such as textiles. Thus, an innovative approach to waste minimization through source reduction has emerged. In the present study, the potential for using colored liquid waste produced in the steam treatment of eucalyptus wood as a natural coloring matter for textile fabrics was investigated. Specifically, eucalyptus wood extract was used to dye cotton, nylon and wool in an exhaust dyeing process without the addition of the traditional mordanting agents. The resulting dyed fabrics were evaluated for color fastness and it was found that wash fastness of eucalyptus wood processing waste dyed fabrics was very good, while light fastness was typical of natural dyes in the absence of mordants.}, journal={JOURNAL OF CLEANER PRODUCTION}, author={Rossi, T. and Silva, P. M. S. and De Moura, L. F. and Araujo, M. C. and Brito, J. O. and Freeman, H. S.}, year={2017}, month={Feb}, pages={303–310} }
 @article{kuenemann_szymczyk_chen_sultana_hinks_freeman_williams_fourches_vinueza_2017, title={Weaver's historic accessible collection of synthetic dyes: a cheminformatics analysis}, volume={8}, ISSN={["2041-6539"]}, DOI={10.1039/c7sc00567a}, abstractNote={The Max Weaver Dye Library is presented to the scientific community with a cheminformatics approach to enhance research opportunities with this unique collection of ∼98 000 vials of custom-made dyes.}, number={6}, journal={CHEMICAL SCIENCE}, author={Kuenemann, Melaine A. and Szymczyk, Malgorzata and Chen, Yufei and Sultana, Nadia and Hinks, David and Freeman, Harold S. and Williams, Antony J. and Fourches, Denis and Vinueza, Nelson R.}, year={2017}, month={Jun}, pages={4334–4339} }
 @article{el-shafei_hinks_boyle_freeman_2015, title={Characterization of non-genotoxic diarylides using experimental and molecular orbital methods}, volume={121}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84930664076&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2015.04.036}, abstractNote={The synthesis of colorants from non-genotoxic benzidine analogs such as 3,3′-dipropoxybenzidine and 2,2′-dimethyl-5,5ʹ-dipropoxybenzidine led to diarylides having atypical physical and chemical properties. For instance, the products obtained from coupling these diamines with acetoacetanilide and acetoacet-p-chloroanilide produced diarylides behaving more like dyes than pigments and thus had significantly lower photostability. In addition, unlike the well-known and widely used commercial diarylide pigments (e.g. CI Pigment Yellow 12) the present compounds had solubility, albeit low, in CHCl3 and CH2Cl2. To account for these observations, the diarylides in our study were characterized using single crystal X-ray crystallography whereupon it was found that they possess varying levels of twist about the biphenyl moiety, impacting the way they pack in the crystal state. The visible spectra for the diarylides were measured in the solid state and in solution, and a 12 nm higher λmax was observed in the solid state for the diarylide derived from 3,3′-dipropoxybenzidine and acetoacetanilde. To account for this λmax change, molecular conformations were probed by 2D dynamic VT-NMR (25–60 °C) in solution using homonuclear 2D-NMR (COSY, COSY-LR, and ROESY), which revealed a single conformation with a torsion angle (θ) across the biphenyl linkage of 56° in solution. The correlation of these results with λmax values for this system is presented.}, journal={DYES AND PIGMENTS}, author={El-Shafei, Ahmed and Hinks, David and Boyle, Paul D. and Freeman, Harold S.}, year={2015}, month={Oct}, pages={128–137} }
 @misc{mehraban_freeman_2015, title={Developments in PDT Sensitizers for Increased Selectivity and Singlet Oxygen Production}, volume={8}, ISSN={["1996-1944"]}, DOI={10.3390/ma8074421}, abstractNote={Photodynamic therapy (PDT) is a minimally-invasive procedure that has been clinically approved for treating certain types of cancers. This procedure takes advantage of the cytotoxic activity of singlet oxygen (1O2) and other reactive oxygen species (ROS) produced by visible and NIR light irradiation of dye sensitizers following their accumulation in malignant cells. The main two concerns associated with certain clinically-used PDT sensitizers that have been influencing research in this arena are low selectivity toward malignant cells and low levels of 1O2 production in aqueous media. Solving the selectivity issue would compensate for photosensitizer concerns such as dark toxicity and aggregation in aqueous media. One main approach to enhancing dye selectivity involves taking advantage of key methods used in pharmaceutical drug delivery. This approach lies at the heart of the recent developments in PDT research and is a point of emphasis in the present review. Of particular interest has been the development of polymeric micelles as nanoparticles for delivering hydrophobic (lipophilic) and amphiphilic photosensitizers to the target cells. This review also covers methods employed to increase 1O2 production efficiency, including the design of two-photon absorbing sensitizers and triplet forming cyclometalated Ir(III) complexes.}, number={7}, journal={MATERIALS}, author={Mehraban, Nahid and Freeman, Harold S.}, year={2015}, month={Jul}, pages={4421–4456} }
 @article{li_freeman_boyter_qian_2015, title={One-Step Pad Dyeing and DP Finishing of Cotton: Part 1. Reactive Dyes with DMDHEU}, volume={2}, ISSN={["2330-5517"]}, DOI={10.14504/ajr.2.3.2}, abstractNote={One-step dyeing and durable press (DP) finishing offers potential advantages such as energy savings, reduced production time, and quick response to the market. In the present research, six reactive dyes were used in combination with DMDHEU, a DP finishing agent, in one-step and conventional two-step dyeing and finishing processes. Colorfastness properties and DP ratings of fabrics treated by the one-step dyeing and finishing process were comparable to those fabrics dyed and finished in separate steps.}, number={3}, journal={AATCC JOURNAL OF RESEARCH}, author={Li, Shiqi and Freeman, Harold S. and Boyter, Henry, Jr. and Qian, Lei}, year={2015}, pages={6–12} }
 @article{li_freeman_boyter_2015, title={One-Step Pad Dyeing and DP Finishing of Cotton: Part 2. Mechanism of Dye Fixation Using DMDHEU}, volume={2}, ISSN={["2330-5517"]}, DOI={10.14504/ajr.2.3.3}, abstractNote={This paper is a follow up to previous work from these laboratories, which led to a method for simultaneous reactive dye fixation and DMDHEU finishing of cotton at significantly higher shade depths (K/S values) than previously reported. The introduction of a steaming step prior to curing was critical to achieving high shade depths. The goal of this report is to present the mechanistic basis for these results. In this regard, results from conducting reactive dye/DMDHEU chemistry on a solid surface and from solvent extractions of dyed cotton before and after powdering indicate that dye fixation occurred by DMDHEU-induced entrapment rather than dye-fiber dye-DMDHEU bond formation.}, number={3}, journal={AATCC JOURNAL OF RESEARCH}, author={Li, Shiqi and Freeman, Harold S. and Boyter, Henry, Jr.}, year={2015}, pages={13–20} }
 @article{franciscon_mendonca_seber_morales_zocolo_zanoni_grossman_durrant_freeman_umbuzeiro_2015, title={Potential of a bacterial consortium to degrade azo dye Disperse Red 1 in a pilot scale anaerobic-aerobic reactor}, volume={50}, ISSN={["1873-3298"]}, DOI={10.1016/j.procbio.2015.01.022}, abstractNote={The textile industry is the largest consumer of azo dyes and activated sludge treatment systems typically used to remove them are frequently inefficient, resulting in significant quantities of these compounds adsorbed in the sludge or released into water bodies. The aim of this study was to evaluate the biodegradation of the commercial azo dye Disperse Red 1 in a pilot scale anaerobic–aerobic reactor inoculated by a microbial consortium selected for its capacity to degrade azo dyes. Dye decolorization (80%) occurred in 60 h in the anaerobic reactor and 92% COD (chemical oxygen demand) was removed as measured in the treated effluent. LC–ESI-MS/MS of the treated effluent showed the formation of a reduced azo bond and azo bond cleavage and subsequent degradation products. Aromatic amines produced by the cleavage of the azo bond were not detected. Toxicity tests performed with Daphnia similis and Hydra attenuata in the treated effluent showed that the toxicity was reduced significantly. Mutagenicity, evaluated using the Salmonella/microsome Ames test, found the untreated dye medium was only mutagenic toward Salmonella strain YG1041. However after treatment, only marginal mutagenicity was observed. These results indicate the bacterial consortium was effective in biodegrading Disperse Red 1 and also reducing the toxicity and mutagenicity and may represent a promising application for dyes biodegradation.}, number={5}, journal={PROCESS BIOCHEMISTRY}, author={Franciscon, Elisangela and Mendonca, Danilo and Seber, Samile and Morales, Daniel Alexandre and Zocolo, Guilherme Juliao and Zanoni, MariaValnice Boldrin and Grossman, Matthew James and Durrant, Lucia Regina and Freeman, Harold S. and Umbuzeiro, Gisela Aragao}, year={2015}, month={May}, pages={816–825} }
 @article{he_freeman_nakpathom_boyle_2015, title={Synthesis and X-ray analysis of a perfluoroalkyl-substituted azobenzene dye}, volume={120}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2015.04.014}, abstractNote={A search for colorants capable of reducing the surface energy of synthetic fibers as well as adding color led to the synthesis and characterization of the repellency behavior of dyes such as 4-N,N-diethylamino-4′-tridecafluorohexylazobenzene. Unexpectedly high surface energy values and a low fluorine content on fiber surfaces then led to an interest in determining the crystal structure of this new dye. Accordingly, a single crystal was grown from acetone solution, and its structure was established using X-ray diffraction analysis. Interestingly, it was found that the azobenzene skeleton is appreciably nonplanar, having an N2–N1–C1–C2 torsion angle of 30.6°, despite the absence of substituents ortho to the azo bond. Further, the structure is characterized by head-to-tail molecular stacking and the N-ethyl groups in the molecule are positioned above the aminobenzene plane on the same side. It is likely that this combination of factors contribute to the observed surface properties of the target dye.}, journal={DYES AND PIGMENTS}, author={He, Liang and Freeman, Harold S. and Nakpathom, Monthon and Boyle, Paul D.}, year={2015}, month={Sep}, pages={245–250} }
 @article{freeman_2013, title={Aromatic amines: use in azo dye chemistry}, volume={18}, ISSN={["1093-9946"]}, DOI={10.2741/4093}, abstractNote={This chapter provides an overview of the chemical structures and properties of aromatic amines and their role in the development and utility of azo dyes. Approaches to the design of environmentally benign alternatives to genotoxic primary aromatic amines, as azo dye precursors, are included.}, journal={FRONTIERS IN BIOSCIENCE-LANDMARK}, author={Freeman, Harold S.}, year={2013}, month={Jan}, pages={145–164} }
 @article{freeman_jeong_claxton_2013, title={Characterization of metabolites of genotoxic 4,4 '-aminoalkoxyazobenzene dyes}, volume={99}, ISSN={["0143-7208"]}, DOI={10.1016/j.dyepig.2013.06.001}, abstractNote={Abstract Invariably these days the molecular design of non-genotoxic azo dyes takes into consideration the potential genotoxicity of aromatic amines arising from reductive cleavage of the azo bonds (–N N–), with those dyes producing carcinogenic amines no longer suitable for commerce. Much less is known about structural factors leading to genotoxic azo dyes having their –N N– bonds intact. This point came to the forefront when it was determined that hydrophobic 4,4′-aminoalkoxyazobenzene dyes such as 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline are mutagenic but their reductive-cleavage products are not. Consequently, a study that was undertaken to unveil the basis for the mutagenic activity of such dyes. The initial study involved the synthesis and evaluation of the mutagenicity of a group of substituted 4,4′-diaminoalkoxyazobenzene dyes, to test our hypothesis which stated that the mutagenicity of 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline arises from the metabolic cleavage of N -hydroxyethyl groups in the parent dye, leading ultimately to 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)aniline. The key goal of the present work was to provide underpinning for results from mutagenicity testing, by isolating and identifying metabolites from S9 treatments. In this regard, title dyes such as 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-hydroxyethyl)aniline were treated with rat or hamster liver S9 in the absence of Salmonella typhimurium and results from TLC and HPLC analysis of product mixtures from S9 treatments indicated that metabolism involved N -dehydroxyethylation to give 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N -(2-hydroxyethyl)-aniline and 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)aniline when rat liver S9 was used and reductive cleavage of the azo bonds to give the corresponding aromatic amines was also observed when hamster liver S9 was used. The analysis of product mixtures further indicated that rat liver S9 metabolism involved deacetylation of O -acetyl groups in the case of 4-(3-(2-hydroxyethoxy-4-amino)phenylazo)- N , N -bis(2-acetoxyethyl)aniline.}, number={2}, journal={DYES AND PIGMENTS}, author={Freeman, Harold S. and Jeong, Euigyung and Claxton, Larry D.}, year={2013}, month={Nov}, pages={496–501} }
 @article{vacchi_albuquerque_vendemiatti_morales_ormond_freeman_zocolo_boldrin zanoni_umbuzeiro_2013, title={Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture}, volume={442}, ISSN={["1879-1026"]}, DOI={10.1016/j.scitotenv.2012.10.019}, abstractNote={Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC–ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1.}, journal={SCIENCE OF THE TOTAL ENVIRONMENT}, author={Vacchi, Francine Inforcato and Albuquerque, Anjaina Fernandes and Vendemiatti, Josiane Aparecida and Morales, Daniel Alexandre and Ormond, Alexandra B. and Freeman, Harold S. and Zocolo, Guilherme Juliao and Boldrin Zanoni, Maria Valnice and Umbuzeiro, Gisela}, year={2013}, month={Jan}, pages={302–309} }
 @article{fadda_el-mekawy_el-shafei_freeman_hinks_el-fedawy_2013, title={Design, Synthesis, and Pharmacological Screening of Novel Porphyrin Derivatives}, volume={2013}, ISSN={["2090-9071"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84874820709&partnerID=MN8TOARS}, DOI={10.1155/2013/340230}, abstractNote={A series of porphyrin derivatives 2a–f was synthesized, namely, 5,10,15,20-mesotetrakis[p-methoxyphenyl]-21H,23H-porphyrin (2a), 5,10,15,20-mesotetrakis[2,6-dichloro-phenyl]-21H,23H-porphyrin (2b), 5,10,15,20-mesotetrakis[4-hydroxy-3,5-dimethoxyphenyl]-21H,23H-porphyrin (2c), 5,10,15,20-mesotetrakis[3,4-dimethoxyphenyl]-21H,23H-porphyrin (2d), 5,10,15,20-mesotetrakis[2,4-dichlorophenyl]-21H,23H-porphyrin (2e), and 5,10,15,20-mesotetrakis[3,4,5-trimethoxyphenyl]-21H,23H-porphyrin (2f), in high yields using a new method via a capping mechanism. These dyes were used as a model to study the free radical-induced damage of biological membranes and the protective effects of these porphyrins. It was demonstrated that these dyes were effective in the inhibition of the free radical-induced oxidative haemolysis of rat blood cells. Dyes 2d and 2f which bear methoxy functionality exhibited markedly higher antihaemolysis activity than the other analogs. Molecular modeling methods using ZINDO/INDO-1, with a configuration interaction of 26, and TD-DFT using the energy functional B3LYP and the basis set DGTZVP were used to study the vertical electronic excitations of porphyrins 2a–f and it was shown that the calculated using TD-DFT method was in excellent agreement with the experimental results, while the ZINDO method was inferior. Moreover, excellent correlation between the LUMO energy and cytotoxicity of dyes 2a–f was found.}, journal={JOURNAL OF CHEMISTRY}, author={Fadda, Ahmed A. and El-Mekawy, Rasha E. and El-Shafei, Ahmed and Freeman, Harold S. and Hinks, David and El-Fedawy, Andmanal}, year={2013} }
 @misc{ormond_freeman_2013, title={Dye Sensitizers for Photodynamic Therapy}, volume={6}, ISSN={["1996-1944"]}, DOI={10.3390/ma6030817}, abstractNote={Photofrin® was first approved in the 1990s as a sensitizer for use in treating cancer via photodynamic therapy (PDT). Since then a wide variety of dye sensitizers have been developed and a few have been approved for PDT treatment of skin and organ cancers and skin diseases such as acne vulgaris. Porphyrinoid derivatives and precursors have been the most successful in producing requisite singlet oxygen, with Photofrin® still remaining the most efficient sensitizer (quantum yield = 0.89) and having broad food and drug administration (FDA) approval for treatment of multiple cancer types. Other porphyrinoid compounds that have received approval from US FDA and regulatory authorities in other countries include benzoporphyrin derivative monoacid ring A (BPD-MA), meta-tetra(hydroxyphenyl)chlorin (m-THPC), N-aspartyl chlorin e6 (NPe6), and precursors to endogenous protoporphyrin IX (PpIX): 1,5-aminolevulinic acid (ALA), methyl aminolevulinate (MAL), hexaminolevulinate (HAL). Although no non-porphyrin sensitizer has been approved for PDT applications, a small number of anthraquinone, phenothiazine, xanthene, cyanine, and curcuminoid sensitizers are under consideration and some are being evaluated in clinical trials. This review focuses on the nature of PDT, dye sensitizers that have been approved for use in PDT, and compounds that have entered or completed clinical trials as PDT sensitizers.}, number={3}, journal={MATERIALS}, author={Ormond, Alexandra B. and Freeman, Harold S.}, year={2013}, month={Mar}, pages={817–840} }
 @article{kim_freeman_2013, title={Effects of bis-carbazole based D-pi-A sensitizers on solar energy capture in DSSCs}, volume={12}, ISSN={["1474-9092"]}, DOI={10.1039/c2pp25262g}, abstractNote={A new series of molecular engineered dyes having a carbazole ( CA ) based bulky donor was synthesized and compared to a previously studied set of dyes having a diphenyl amine ( DP ) donor for their use in dye sensitized solar cells. In this work, their photophysical, electrochemical, and kinetic properties were measured and molecular modeling methods were used to predict their electronic and physical properties. Regarding the latter, TDDFT studies adopting different exchange correlation functionals were performed to predict solar capture behavior of these sensitizers. The calculated electronic energies showed that the introduction of the bulky CA donor gave a greater negative shift on E _HOMO rather than E _LUMO, imparting the CA series of dyes a red shifted absorption. On the other hand, tuning of the spacer unit by using different heterocylic rings was sensitive to the shift of E _LUMO shift. Better light absorption and driving force of devices based on the CA series were counteracted with negative effects related to the electron injection yield and electron recombination lifetime. The origin of the lower efficiency of the CA dye based devices was investigated in terms of dye load, charge recombination lifetime, in tandem with modeling studies. Results from assessing the effects of different heterocyclic rings, as a π conjugation unit on photovoltaic performance showed that the thiophene unit gave the highest current. On the other hand, CA - and DP -based dyes having an N -methyl pyrrole unit afforded the highest V _oc. The best DSSC performance in the CA series was achieved by the thiophene derivative, where η = 3.05% with J _sc = 6.29 mA cm^−2, V _oc = 673 mV and FF = 0.72 under 100 mW m^−2 irradiation.}, number={3}, journal={PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES}, author={Kim, Bo Hyung and Freeman, Harold S.}, year={2013}, pages={421–431} }
 @article{ormond_freeman_2013, title={Effects of substituents on the photophysical properties of symmetrical porphyrins}, volume={96}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2012.09.011}, abstractNote={Porphyrin compounds having groups that mimic the phenolic moiety of m- and p-isomers of 5,10,15,20-tetrakis(hydroxyphenyl) porphyrin (THPP) have been synthesized along with 5,10,15,20-tetrakis(heteroaryl) porphyrins bearing 2-thienyl and 5-thiazolyl groups. Absorption and fluorescence spectroscopy, including fluorescence lifetime (τf) and quantum yield (Φf) measurements, were employed to characterize the singlet excited state of all compounds, using 5,10,15,20-tetraphenylporphyrin (H2TPP) as a standard (Φf = 0.12 in DMF). The generation of singlet oxygen by each porphyrin photosensitizer was measured as the singlet oxygen quantum yield (ΦΔ), using H2TPP as a standard (ΦΔ = 0.64 in DMF). Partition coefficients were determined using 2-octanol as the organic phase and PBS solution as the aqueous phase. Fluorescence quantum yields ranged from 0.01 to 0.18 for all compounds, with heteroaryl porphyrins having the lowest values. Singlet oxygen quantum yields ranged from 0.40 to 0.65, with heteroaryl porphyrins having the highest values, showing them to be better sensitizers than m- and p-THPP. Log P values were all >1 showing higher solubility in the 2-octanol layer.}, number={2}, journal={DYES AND PIGMENTS}, author={Ormond, Alexandra B. and Freeman, Harold S.}, year={2013}, month={Feb}, pages={440–448} }
 @article{kim_freeman_2013, title={New N-methyl pyrrole and thiophene based D-pi-A systems for dye-sensitized solar cells}, volume={96}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2012.09.001}, abstractNote={Dye-sensitized solar cells (DSSCs) containing novel DP-T and DP-P organic sensitizers having thiophene and N-methyl pyrrole moieties as π bridges in a D–π–A system were assembled and characterized. Incorporation of a thiophene bridge to give sensitizer DP-T enhanced solar energy capture, while impedance spectroscopy showed a much longer electron recombination lifetime (τ) for the DSSCs based on pyrrole containing sensitizer DP-P. The observed kinetics led to increased open circuit voltage (Voc) for the device based on DP-P, regardless of types of additives (TBP or DCA) employed in the devices. Better photovoltaic performance was achieved using DP-T.}, number={2}, journal={DYES AND PIGMENTS}, author={Kim, Bo Hyung and Freeman, Harold S.}, year={2013}, month={Feb}, pages={313–318} }
 @article{fadda_el-mekawy_el-shafei_freeman_2013, title={Synthesis and Pharmacological Screening of Novel meso-Substituted Porphyrin Analogs}, volume={346}, ISSN={["0365-6233"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-84872271916&partnerID=MN8TOARS}, DOI={10.1002/ardp.201200313}, abstractNote={Abstract}, number={1}, journal={ARCHIV DER PHARMAZIE}, author={Fadda, Ahmed A. and El-Mekawy, Rasha E. and El-Shafei, Ahmed I. and Freeman, Harold}, year={2013}, month={Jan}, pages={53–61} }
 @article{lu_he_zhang_freeman_2012, title={Novel yellow azo-anthraquinone dyes for polylactide fibres: effects of alkyl chain length}, volume={128}, ISSN={["1472-3581"]}, DOI={10.1111/j.1478-4408.2011.00354.x}, abstractNote={1‐(4′‐Alkylaminosulphurylphenyl)‐3‐methyl‐5‐pyrazolonyl azo–anthraquinone dyes were prepared in four steps from 1‐aminoanthraquinone, as an approach to enhancing the exhaustion levels of disperse dyes on polylactide fibres. Their structures were confirmed from combustion analysis and mass spectrometry, infrared and proton nuclear magnetic resonance spectroscopy. Results from artificial intelligence‐based molecular modelling studies showed that increasing alkyl chain length gave an increase in LogP, molecular volume and aplanar shape. Their application to polylactide fibres led to both good per cent exhaustion values and good light fastness ratings. It was also found that the nature of the alkyl chains attached to the phenyl ring had little influence on dye colour, but clearly influenced per cent exhaustion and wash fastness.}, number={2}, journal={COLORATION TECHNOLOGY}, author={Lu, Lihua and He, Liang and Zhang, Shufen and Freeman, Harold S.}, year={2012}, month={Apr}, pages={121–126} }
 @article{kim_freeman_2012, title={Structure-photovoltaic performance relationships for DSSC sensitizers having heterocyclic and benzene spacers}, volume={22}, ISSN={["1364-5501"]}, DOI={10.1039/c2jm33228k}, abstractNote={Five new sensitizers based on different spacer groups were designed and synthesized in order to facilitate investigation of the effects of heterocyclic spacers on photovoltaic parameters in DSSCs. It was found that generic issues arising from the electronic nature of heterocyclic units affected voltage parameters, with DP-P giving the highest voltage. On the other hand, higher electron transfer yield across a wide range of the solar spectrum played an important role in enhanced current densities. Best performance was achieved by the thiophene based sensitizer DP-T, resulting in an efficiency of 3.5% with Jsc = 8.19 mA cm−2, Voc = 0.618 V, ff = 0.697.}, number={38}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Kim, Bo Hyung and Freeman, Harold S.}, year={2012}, pages={20403–20409} }
 @article{he_freeman_lu_zhang_2011, title={Spectroscopic study of anthraquinone dye/amphiphile systems in binary aqueous/organic solvent mixtures}, volume={91}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2011.05.010}, abstractNote={The absorption spectra of novel dye/amphiphile systems, in which the dye is a 1,5-bis-(R-phenylamino)anthraquinone [R = o-methoxy, o-ethoxy, H] and the solvents are either organic or H2O/organic solvent mixtures, have been investigated. It was found that an abrupt λmax shift of more than 80 nm occurred for the system containing dye having R = o-methoxy and the amphiphile (poly-bis-(2,2′-dimethyl-5,5′-disulphonate)naphthylmethane disodium salt) in pure solvents with a specific ET(30) value or in H2O/DMF (N,N-dimethylformamide) mixtures containing at least 38% water. This type λmax shift was not observed when solvent mixtures containing the other two dyes were studied. The origin of the pronounced λmax shift is discussed in detail. It is believed that this shift arises mainly from changes in the solvation state of hydrophobic dye having R = o-methoxy when water is introduced in the presence of a dispersing agent. In this regard, dye is converted from the monomolecular state to dispersed particles.}, number={3}, journal={DYES AND PIGMENTS}, author={He, Liang and Freeman, Harold S. and Lu, Lihua and Zhang, Shufen}, year={2011}, month={Dec}, pages={389–395} }
 @article{he_gong_freeman_jian_chen_zhao_2011, title={Studies involving reactive dyes containing a benzophenone ultraviolet absorber}, volume={127}, ISSN={["1478-4408"]}, DOI={10.1111/j.1478-4408.2010.00277.x}, abstractNote={Nine new fibre reactive dyes containing a built‐in hydroxybenzophenone moiety were synthesised, characterised using electrospray mass spectroscopic analysis, applied to cotton fabrics and the ultraviolet protection factor values of the dyed cotton fabrics determined. The results showed that the anti‐ultraviolet properties of cotton were improved by dyeing with dyes containing a built‐in hydroxybenzophenone moiety, but that the benzophenone ultraviolet absorber need not be covalently linked to dye molecules to provide significant benefit.}, number={1}, journal={COLORATION TECHNOLOGY}, author={He, Liang and Gong, Guoliang and Freeman, Harold S. and Jian, Wei and Chen, Meifen and Zhao, Defeng}, year={2011}, pages={47–54} }
 @article{liang_han_shen_wang_zhao_freeman_2010, title={Palladium nanoparticle microemulsions: Formation and use in catalytic hydrogenation of o-chloronitrobenzene}, volume={165}, ISSN={["1873-3212"]}, DOI={10.1016/j.cej.2010.10.022}, abstractNote={The formation and catalytic properties of well-dispersed palladium (Pd) nanoparticles in water-in-oil (w/o) microemulsions containing octadecyl amine polyoxyethylene ether (OAPE-5) and hydrogenated tallow amine (HTA) have been investigated. The size and structure of the nanoparticles were characterized by TEM and XRD analyses and the effects of microemulsion composition on particle sizes were assessed using FTIR spectroscopy. The results of TEM and XRD indicated that the particles were of a face centered cubic structure form and their mean diameter was 10 nm. Results of FTIR analysis indicated strong interactions between Pd nanoparticles and surfactant molecules. Use of these Pd nanoparticles for the hydrogenation of o-chloronitrobenzene in the presence of alkali produced a 3:1 ratio of aniline to o-chloroaniline and none of the frequently observed nitrobenzene or 2,2′-dichlorohydrazoebenzene.}, number={2}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Liang, Chunhua and Han, Jianguo and Shen, Kaihua and Wang, Legang and Zhao, Defeng and Freeman, Harold S.}, year={2010}, month={Dec}, pages={709–713} }
 @article{he_lu_zhang_freeman_2010, title={Synthesis and application of yellow azo-anthraquinone disperse dyes for polylactide fibres}, volume={126}, ISSN={["1472-3581"]}, DOI={10.1111/j.1478-4408.2010.00232.x}, abstractNote={1‐Phenyl‐3‐methyl‐5‐pyrazolonyl azo‐anthraquinone dyes having high light fastness on polylactide fibres were synthesised from 1‐aminoanthraquinone via a diazotisation‐coupling reaction with 1‐phenyl‐3‐methyl‐5‐pyrazolones. The structures of these new dyes were confirmed using mass spectrometry, infrared and proton nuclear magnetic resonance spectroscopy and combustion analyses. Their dyeing behaviour on polylactide fibres was also determined, whereupon it was found that the title dyes could be applied at a relatively low dyeing temperature and that the corresponding dyed fabrics had good fastness properties.}, number={2}, journal={COLORATION TECHNOLOGY}, author={He, Liang and Lu, Lihua and Zhang, Shufen and Freeman, Harold S.}, year={2010}, pages={92–96} }
 @misc{jeong_freeman_claxton_2010, title={Synthesis and characterization of selected 4,4 '-diaminoalkoxyazobenzenes}, volume={87}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2010.03.002}, abstractNote={Abstract The role of the –N(CH2CH2OH)2 group in producing a mutagenic response from 4-((3-(2-hydroxyethoxy)4-amino)phenylazo)-N,N-bis(2-hydroxyethyl)aniline has been investigated. To accomplish this goal, a group of substituted 4,4′-diaminoazobenzene dyes was synthesized, and their structures were confirmed using 1H NMR, TOF-LC-ESI mass spectrometry, and combustion analysis. Mutagenicity was determined using the standard Ames test in Salmonella strains TA98, TA100, and TA1538 with and without S9 enzyme activation. The results of this study provide evidence that the mutagenicity of the parent dye arises from the metabolic cleavage of N-hydroxyethyl groups to give the corresponding –NHCH2CH2OH and –NH2 substituted monoazo dyes as direct-acting mutagens. All 5 of the dyes studied were mutagenic at various levels with and without S9 enzyme activation in TA1538. In addition, the results show that removing one N-hydroxyethyl group and capping both –OH groups in the parent dye did not affect mutagenicity, whereas removing both N-hydroxyethyl groups produced a strong direct-acting mutagen in all three bacterial strains. Increasing the length of the N-alkyl chain from two to three carbon atoms eliminated mutagenicity in TA98 without S9 activation.}, number={2}, journal={DYES AND PIGMENTS}, author={Jeong, Euigyung and Freeman, Harold S. and Claxton, Larry D.}, year={2010}, month={Oct}, pages={100–108} }
 @article{zhi-gang_chun-xia_de-feng_freeman_pei-tong_jie_2009, title={Monoazo dyes based on 5,10-dihydrophenophosphazine, Part 2: Azo acid dyes}, volume={81}, ISSN={["0143-7208"]}, DOI={10.1016/j.dyepig.2008.09.021}, abstractNote={2-Amino-5,10-dihydro-10-hydroxyphenophosphazine 10-oxide, a non-mutagenic aromatic amine, was diazotized and combined with various sulfonated naphthalene-based coupling components to give new monoazo dyes, the structures of which were confirmed using mass spectrometric and NMR analyses. Investigation of the properties of the target colorants as acid dyes indicated that they furnished deep shades on wool and silk; those dyes containing only one sulfonic acid group gave black shades on wool at 3% omf depth of shade whilst three of these dyes gave bluish-black shades and one gave a reddish-black shade on wool. The black color of the four shades was similar to that obtained using C.I. Acid Black 1 and the resultant fastness properties were generally good.}, number={2}, journal={DYES AND PIGMENTS}, author={Zhi-Gang, Yin and Chun-Xia, Zhang and De-Feng, Zhao and Freeman, Harold S. and Pei-Tong, Chen and Jie, Hu}, year={2009}, month={May}, pages={137–143} }
 @article{he_el-shafei_freeman_boyle_2009, title={X-ray and molecular modelling studies of 4-[N-alkylamino]azobenzene dyes}, volume={82}, ISSN={["1873-3743"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-64849101647&partnerID=MN8TOARS}, DOI={10.1016/j.dyepig.2009.01.013}, abstractNote={Abstract 4-[N,N-Bisalkyl]amino-2′-chloro-4′-nitroazobenzenes were recrystallized from acetone in either triclinic or monoclinic cells with the space group P-1 or P21/c. The asymmetric unit cell of dyes having at least one N-cyanoethyl group contained two molecules that were symmetrically unequivalent. The aromatic rings in the azobenzene skeleton were essentially planar with respect to the plane of the azo group, although the C6–C1–N1–N2 torsion angle was 13.2° when the N,N-dicyanoethyl group was employed. X-ray studies were used as a basis for assessing the utility of nonlocal DFT calculations in predicting the equilibrium molecular geometry and solvatochromic properties of the compounds using MM3/ZINDO-S and the COSMO Solvation Model. Although B3LYP and PBE energy functionals were comparable in predicting bond lengths, PBE was slightly better than B3LYP in predicting torsion angles. Furthermore, the dipolarity/polarizability index (π∗) was the preferred solvent parameter for predicting the effects of solvents on λmax.}, number={3}, journal={DYES AND PIGMENTS}, author={He, Liang and El-Shafei, Ahmed and Freeman, Harold S. and Boyle, Paul}, year={2009}, month={Sep}, pages={299–306} }
 @article{zhang_wang_shen_zhao_freeman_2008, title={Hydrogenation of o-chloronitrobenzene on a Pd/C catalyst doped with metal oxide nanoparticles}, volume={141}, ISSN={["1385-8947"]}, DOI={10.1016/j.cej.2008.04.006}, abstractNote={Pd/C catalysts doped with cerium oxide and iron oxide nanoparticles were prepared by thermal decarboxylation in the presence of cetylsulfonyl acetate, and used in the hydrogenation of o-chloronitrobenzene to give high yields of 2,2′-dichlorohydrazobenzene. It was found that the stability and activity of the Pd/C catalysts were significantly affected by doping with the nanosized metal oxides. The chemical structure of 2,2′-dichlorohydrazobenzene was confirmed by 1H and 13C NMR spectroscopy.}, number={1-3}, journal={CHEMICAL ENGINEERING JOURNAL}, author={Zhang, Gang and Wang, Legang and Shen, Kaihua and Zhao, Defeng and Freeman, Harold S.}, year={2008}, month={Jul}, pages={368–374} }
 @article{nayar_freeman_2008, title={Hydrolyzed reactive dyes. Part 1: Analyses via fast atom bombardment and electrospray mass spectrometry}, volume={79}, ISSN={["0143-7208"]}, DOI={10.1016/j.dyepig.2007.07.002}, abstractNote={This paper provides a summary of results from the use of negative ion fast atom bombardment (FAB) and negative ion electrospray (ES) mass spectrometry to characterize dye structures remaining following the dyeing of cotton with reactive dyes. It was found that the ES method gave peaks of higher relative abundance in the molecular weight region and better signal to noise ratios than the FAB ionization process.}, number={2}, journal={DYES AND PIGMENTS}, author={Nayar, Sachin B. and Freeman, Harold S.}, year={2008}, month={Nov}, pages={89–100} }
 @article{ahmadi_kish_freeman_kotek_katbab_2008, title={Photostability of isotactic polypropylene containing monoazo pigment}, volume={108}, ISSN={["1097-4628"]}, DOI={10.1002/app.27951}, abstractNote={Abstract}, number={5}, journal={JOURNAL OF APPLIED POLYMER SCIENCE}, author={Ahmadi, Zahra and Kish, Mohammad Haghighat and Freeman, Harold and Kotek, Richard and Katbab, Ali Asghar}, year={2008}, month={Jun}, pages={2950–2957} }
 @article{bae_freeman_2007, title={Aquatic toxicity evaluation of copper-complexed direct dyes to the Daphnia magna}, volume={73}, ISSN={["0143-7208"]}, DOI={10.1016/j.dyepig.2005.10.019}, abstractNote={The aquatic toxicity of a series of copper-complexed direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine, were evaluated in acute toxicity studies using Daphnia magna. The purpose of the research described in this paper was to use bioassays with daphnids to determine the aquatic toxicity of metallized direct dyes synthesized. The results clearly show that all of the copper-complexed dyes examined were highly toxic to daphnids and more toxic than unmetallized new direct dyes as expected. The study also suggested that the assay with D. magna was an excellent method for evaluation of dyes for aquatic toxicity.}, number={1}, journal={DYES AND PIGMENTS}, author={Bae, Jin-Seok and Freeman, Harold S.}, year={2007}, pages={126–132} }
 @article{bae_freeman_2007, title={Aquatic toxicity evaluation of new direct dyes to the Daphnia magna}, volume={73}, ISSN={["0143-7208"]}, DOI={10.1016/j.dyepig.2005.10.015}, abstractNote={The aquatic toxicity of a series of new direct dyes based on benzidine congeners, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine, and a commercial dye (C.I. Direct Blue 218) were evaluated in acute toxicity studies using Daphnia magna. The purpose of the research described in this paper was to use bioassays with daphnids to determine the aquatic toxicity of new direct dyes synthesized. The results clearly show that C.I. Direct Blue 218 examined was highly toxic to daphnids and more toxic than unmetallized new direct dyes as expected. The study also suggested that the assay with D. magna was an excellent method for evaluation of dyes for aquatic toxicity.}, number={1}, journal={DYES AND PIGMENTS}, author={Bae, Jin-Seok and Freeman, Harold S.}, year={2007}, pages={81–85} }
 @article{szymczyk_el-shafei_freeman_2007, title={Design, synthesis, and characterization of new iron-complexed azo dyes}, volume={72}, ISSN={0143-7208}, url={http://dx.doi.org/10.1016/j.dyepig.2005.07.009}, DOI={10.1016/j.dyepig.2005.07.009}, abstractNote={As part of a continuing study pertaining to the use of Fe as a substitute for metals such as Cr and Co in the design and synthesis of metal-complexed azo and formazan dyes, the synthesis of dye ligands containing ortho-trifluoroacetamido or mesylamido groups in the diazo components was undertaken. It was anticipated that these groups would mimic the acidity and metallizing properties of an ortho-OH group, thus producing new Fe-complexed dyes. The target ligands were synthesized in 4–5 steps and 80–91% yields from commercially available intermediates. 1H NMR was used to confirm the structures of the target dye ligands. The resultant azo and formazan systems readily formed 1:2 Fe-complexes when an ortho-NHSO2Me group was employed, while preparation of Fe-complexes from dye ligands having an ortho-NHCOCF3 group proved difficult, with mixtures of unmetallized dye, Fe-complex, and Fe hydroxide obtained despite variations in reaction conditions. Results of DFT calculations suggest that electron density at the N-22 atom was significantly diminished by the electron-withdrawing power of the CF3 moiety, inhibiting complex formation.}, number={1}, journal={Dyes and Pigments}, publisher={Elsevier BV}, author={Szymczyk, Malgorzata and El-Shafei, Ahmed and Freeman, Harold S.}, year={2007}, month={Jan}, pages={8–15} }
 @article{reife_freeman_2007, title={Dyes for polyester: disperse dyes}, volume={25}, number={4}, journal={Chimica Oggi}, author={Reife, A. and Freeman, H. S.}, year={2007}, pages={38–41} }
 @article{ahmadi_kish_freeman_kotek_katbab_2007, title={Photo-stability of pigmented isotactic polypropylene}, volume={104}, journal={Journal of Applied Polymer Science}, author={Ahmadi, Z. and Kish, M. H. and Freeman, H. and Kotek, R. and Katbab, A. A.}, year={2007} }
 @article{wang_freeman_d claxton_2007, title={Synthesis and mutagenic properties of 4,4'-diamino-p-terphenyl and 4,4'-diamino-p-quaterphenyl}, volume={123}, ISSN={["1472-3581"]}, DOI={10.1111/j.1478-4408.2006.00058.x}, abstractNote={4,4′‐Diamino‐p‐terphenyl and 4,4′‐diamino‐p‐quaterphenyl were synthesised from readily available chemical intermediates. These compounds, along with 1,4‐diaminophenylene and benzidine were examined in the Salmonella microsome assay with strains TA98 and TA100. The results of this study indicate that the mutagenicity of these diamines was the greatest for 4,4′‐diamino‐p‐terphenyl, followed by diaminophenylene and benzidine, with 4,4′‐diamino‐p‐quaterphenyl showing no mutagenicity.}, number={1}, journal={COLORATION TECHNOLOGY}, author={Wang, Jinlong and Freeman, Harold S. and D Claxton, Larry}, year={2007}, pages={34–38} }
 @article{wang_freeman_d claxton_2007, title={Synthesis and mutagenic properties of direct dyes from 4,4'-diamino-p-terphenyl and 4,4'-diamino-p-quaterphenyl}, volume={123}, ISSN={["1472-3581"]}, DOI={10.1111/j.1478-4408.2006.00059.x}, abstractNote={Disazo direct dyes were synthesised using bis‐diazotisation and coupling reactions involving 4,4′‐diamino‐p‐terphenyl and 4,4′‐diamino‐p‐quaterphenyl. The formation of the target dyes was confirmed by electrospray mass spectrometry and their mutagenicity was examined in the Salmonella microsome assay using TA98 and TA100. While most of these dyes were clearly non‐mutagenic, results from the Prival modification of the standard assay showed that Congo Red and its homologue derived from 4,4′‐diamino‐p‐terphenyl were clearly mutagenic.}, number={1}, journal={COLORATION TECHNOLOGY}, author={Wang, Jinlong and Freeman, Harold S. and D Claxton, Larry}, year={2007}, pages={39–45} }
 @article{sun_zhao_freeman_2007, title={Synthesis and properties of disperse dyes containing a built-in triazine stabilizer}, volume={74}, ISSN={["1873-3743"]}, DOI={10.1016/j.dyepig.2006.04.001}, abstractNote={Novel monoazo disperse dyes containing a built-in triazine moiety have been synthesized and evaluated for their ability to give protection against the harmful effects of UV radiation. The results showed that some of the new dyes have the properties needed to provide enhanced skin protection following their incorporation into polyester fabric. It was also found that in certain cases, protection against UV radiation diminished slightly after washing the fabric.}, number={3}, journal={DYES AND PIGMENTS}, author={Sun, Yanfeng and Zhao, Defeng and Freeman, Harold S.}, year={2007}, pages={608–614} }
 @article{suwanruji_freeman_2006, title={Design, synthesis and application of easy wash-off reactive dyes}, volume={122}, ISSN={["1478-4408"]}, DOI={10.1111/j.1478-4408.2006.00002.x}, abstractNote={New dyes that not only give good fixation levels but also relatively low substantivity in the hydrolysed form were the targets of this research. Our approach involved lowering the substantivity of the hydrolysed dye by reducing the planarity that is required for dyes to have high substantivity on cotton. In this regard, bifunctional bis‐dichlorotriazine (bis‐DCT) and tetrafunctional bis‐monochlorotriazine/bis‐sulphatoethyl sulphone [bis‐(MCT/SES)] reactive dyes were made, using selected diaminobiphenyls. Bis‐DCT bifunctional reactive dyes were applied to cotton by a pad–batch method, while bis‐(MCT/SES) tetrafunctional reactive dyes were applied to cotton by a pad–dry–cure. Following dye application, it was found that the resultant hydrolysed dyes easily washed off the fibre surface and that the dyed cotton fabrics had colour fastness to rubbing and laundering properties that were comparable with the commercial prototypes used in this study. However, it is also apparent that the combination of relatively low water solubility and large molecular size has an adverse effect on fibre penetration.}, number={1}, journal={COLORATION TECHNOLOGY}, author={Suwanruji, P and Freeman, HS}, year={2006}, pages={27–36} }
 @article{bae_freeman_warren_claxton_2006, title={Evaluation of new 2,2 '-dimethyl-5,5 '-dipropoxybenzidine- and 3,3 '-dipropoxybenzidine-based direct dye analogs for mutagenic activity by use of the Salmonella/mammalian mutagenicity assay}, volume={603}, ISSN={["1879-3592"]}, DOI={10.1016/j.mrgentox.2005.11.007}, abstractNote={As part of a continuing study aimed at establishing structure–activity relationships and heuristic principles useful for the design of non-genotoxic azo dyes, a series of new direct dyes based on two non-mutagenic benzidine analogs, 2,2′-dimethyl-5,5′-dipropoxybenzidine and 3,3′-dipropoxybenzidine, were evaluated for mutagenic activity in Salmonella typhimurium strains TA98 and TA100. These strains are widely used for mutagenicity screening and have been shown to detect the mutagenic activity of benzidine analogs. While some toxicity was seen with some dyes at high doses, all of the dyes examined were judged non-mutagenic with and without metabolic activation in the standard Salmonella plate-incorporation assay. The results in the standard test are consistent with the properties of the diamines themselves. However, only one of the dyes was non-mutagenic when a reductive-metabolism pre-incubation assay was used. The results of this study suggest that although benzidine analogs are potential replacements for benzidine, there is a need to understand which mutagenic products are produced when reductive metabolism is present. There is also a need to know whether or not metal complexes of these dyes are mutagenic. Such information will allow the development of new non-mutagenic azo dyes.}, number={2}, journal={MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS}, author={Bae, JS and Freeman, HS and Warren, SH and Claxton, LD}, year={2006}, month={Feb}, pages={173–185} }
 @article{freeman_suwanruji_2006, title={Fiber reactive dyes}, volume={53}, number={4}, journal={Colourage Annual}, author={Freeman, H.S. and Suwanruji, P.}, year={2006}, pages={85–101} }
 @article{smith_berger_freeman_2006, title={High affinity, high efficiency fibre-reactive dyes}, volume={122}, ISSN={["1472-3581"]}, DOI={10.1111/j.1478-4408.2006.00032.x}, abstractNote={A straightforward two‐step method for modifying commercial dichlorotriazine‐based fibre‐reactive dyes prior to their use in the dyeing process can greatly improve affinity and fixation efficiency on cotton, and reduce the salt requirements. The modification used in this study involved prereacting the commercial dyes with either cysteine or cysteamine followed by reaction of the resulting intermediate with cyanuric chloride. Cotton fabric dyed with the modified dyes had technical properties that were essentially equal to those obtained from the unmodified commercial dyes.}, number={4}, journal={COLORATION TECHNOLOGY}, author={Smith, Brent and Berger, Rebecca and Freeman, Harold S.}, year={2006}, pages={187–193} }
 @article{bae_freeman_kim_2006, title={Influences of new azo dyes to the aquatic ecosystem}, volume={7}, ISSN={["1229-9197"]}, DOI={10.1007/BF02933599}, number={1}, journal={FIBERS AND POLYMERS}, author={Bae, JS and Freeman, HS and Kim, SD}, year={2006}, month={Mar}, pages={30–35} }
 @article{volna_holcapek_suwanruji_freeman_2006, title={Mass spectrometric analysis of sulphonated dyes based on diaminobiphenyls}, volume={122}, ISSN={["1478-4408"]}, DOI={10.1111/j.1478-4408.2006.00001.x}, abstractNote={The title dyes, a group of new homo‐bireactive disazo reactive dyes having molecular masses of 1000–1400 Da, were developed because of their potential use as low salt, easy wash‐off colorants for cotton. Following dye synthesis from diaminobiphenyls with and without substituents in the 2,2′‐positions, negative‐ion electrospray ionisation mass spectrometry (ESI‐MS) was used to characterise the dyes. The MS obtained were characterised by signals arising from [M − xH]x− ions plus fragment ions produced by cleavage at C–N bonds adjacent to the azo linkage. In addition, better results were produced when J‐acid was the coupler employed rather than H‐acid. The characteristic fragmentation behaviour of the studied dyes is discussed and illustrated on selected example.}, number={1}, journal={COLORATION TECHNOLOGY}, author={Volna, K and Holcapek, M and Suwanruji, P and Freeman, HS}, year={2006}, pages={22–26} }
 @article{jenkins_el-tahlawy_el-shafei_freeman_hudson_2006, title={Use of gamma-cyclodextrin/epichlorohydrin polymer in merging fabric formation and coloration processes}, volume={122}, ISSN={["1472-3581"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-33751023859&partnerID=MN8TOARS}, DOI={10.1111/j.1478-4408.2006.00051.x}, abstractNote={A candidate polymeric size was synthesised by the polymerisation of γ‐cyclodextrin with epichlorohydrin under alkaline conditions. The motivation for the synthesis was to produce a polymer that could not only function as a warp size for fabric formation, but also serve as a host for dye molecules that could subsequently be released after the weaving process, ultimately promoting the merging of fabric formation and coloration processes. The γ‐cyclodextrin/epichlorohydrin polymer has been found to promote the dissolution of textile dyes, such as CI Disperse Blue 3, CI Disperse Yellow 82 and CI Disperse Red 91 to yield pad baths capable of evenly coating polyester fabric. Upon padding and subsequent drying, the dye–γ‐cyclodextrin/epichlorohydrin polymer pad baths have been used for dyeing the fabric upon thermofixation. Furthermore, cross‐sections of fibre dyed in the same manner indicate dye penetration into the fibre.}, number={6}, journal={COLORATION TECHNOLOGY}, author={Jenkins, David W. and El-Tahlawy, Khaled and El-Shafei, Ahmed and Freeman, Harold S. and Hudson, Samuel M.}, year={2006}, pages={345–349} }
 @article{pielesz_weselucha-birczynska_freeman_wlochowicz_2005, title={Characterizing of model direct dyes interactions with cotton cellulose via 1D and 2D Raman spectroscopy}, volume={12}, ISSN={["1572-882X"]}, DOI={10.1007/s10570-005-7132-6}, number={5}, journal={CELLULOSE}, author={Pielesz, A and Weselucha-Birczynska, A and Freeman, HS and Wlochowicz, A}, year={2005}, month={Oct}, pages={497–506} }
 @article{bae_freeman_2005, title={Evaluation of new direct dyes for mutagenicity using the Salmonella mammalian mutagenicity assay}, volume={6}, ISSN={["1875-0052"]}, DOI={10.1007/BF02875665}, number={4}, journal={FIBERS AND POLYMERS}, author={Bae, JS and Freeman, HS}, year={2005}, month={Dec}, pages={297–305} }
 @article{bae_freeman_2005, title={Evaluation of new metallized direct dyes for mutagenicity using the Salmonella mammalian mutagenicity assay}, volume={6}, ISSN={["1229-9197"]}, DOI={10.1007/BF02875648}, number={3}, journal={FIBERS AND POLYMERS}, author={Bae, JS and Freeman, HS}, year={2005}, month={Sep}, pages={235–243} }
 @article{umbuzeiro_freeman_warren_kummrow_claxton_2005, title={Mutagenicity evaluation of the commercial product CI Disperse Blue 291 using different protocols of the Salmonella assay}, volume={43}, ISSN={["1873-6351"]}, DOI={10.1016/j.fct.2004.08.011}, abstractNote={Textile dyes can enter the water ecosystem through wastewater discharges potentially exposing humans through the consumption of water and food. The commercial disperse dye product CI Disperse Blue 291 containing the aminoazobenzene 2-[(2-bromo-4,6-dinitrophenyl)azo]-5-(diethylamino)-4-methoxyacetanilide (CAS registry no. 56548-64-2) was tested for mutagenic activity in the Salmonella assay. We used strains with different levels of nitroreductase and O-acetyltransferase (i.e., TA98DNP6, YG1024, and YG1041) that are relevant enzymes in the activation of nitrocompounds by the intestinal microflora. The commercial product tested also was mutagenic for TA1537, TA1538, TA98 and TA100. Presence of the pKM101 plasmid and the addition of S9 enhanced the mutagenic response. Specialized strains showed that both nitroreductase and O-acetyltransferase are important in activation of the product. The highest potency obtained was 240 revertants per microgram for YG1041 in the presence of S9. Besides being able to cause frameshift mutations (hisd3052), the dye was able to cause all types of base pair substitution with a preference for TA to AT; CG to TA and CG to AT changes. With these results clearly showing that the bacterial nitroreductase and O-acetyltransferase metabolites of this compound are mutagenic, there is a need to test this dye using in vivo systems to verify possible adverse effects of this product in mammalian tissues.}, number={1}, journal={FOOD AND CHEMICAL TOXICOLOGY}, author={Umbuzeiro, GD and Freeman, H and Warren, SH and Kummrow, F and Claxton, LD}, year={2005}, month={Jan}, pages={49–56} }
 @article{edwards_freeman_2005, title={Synthetic dyes based on environmental considerations. Part 3: Aquatic toxicity of iron-complexed azo dyes}, volume={121}, DOI={10.1111/j.1478-4408.2005.tb00284.x}, abstractNote={In previous papers it has been shown that chromium or cobalt in metal-complexed azo dyes can be replaced by iron without adversely affecting the dyeing or mutagenic properties. Before commercial exploitation could be considered, an assessment of the aquatic toxicity of the iron complex dyes was important. The effect of replacing chromium and cobalt with iron on the aquatic toxicity of metal complex acid dyes for polyamide and protein substrates has been assessed in terms of the effect on Lemna minor (duckweed). A similar assessment has been carried out to show the effect on toxicity of dyebath decolorisation using ozonolysis. The results confirm that iron-complexed dyes are generally less toxic than the corresponding chromium or cobalt complexes, and that ozonolysis of aqueous solutions causes an increase in both pH and toxicity to Lemna minor. Received: 30 April 2005; Accepted: 23 June 2005.}, number={5}, journal={Coloration Technology}, author={Edwards, L. C. and Freeman, H. S.}, year={2005}, pages={265–270} }
 @article{edwards_freeman_2005, title={Synthetic dyes based on environmental considerations. Part 4: Aquatic toxicity of iron-complexed formazan dyes}, volume={121}, DOI={10.1111/j.1478-4408.2005.tb00285.x}, abstractNote={It has been shown in previous papers that iron can replace toxic metals such as chromium and cobalt in a range of azo metal complexes without adversely affecting their technical or mutagenic properties. Part 3 of this series reported aquatic toxicity assessment of a series of iron complex azo dyes using Lemna minor. The present paper extends this to a range of formazan dyes. The effect on aquatic toxicity of using iron as the complexing metal, and of dyebath decolorisation by ozonolysis, have been examined. The results confirm that iron-complexed formazan dyes are generally nontoxic. On the other hand, unlike the azo dyes studied previously, ozonolysis of aqueous solutions of iron complex formazan dyes was not found to cause a decrease in pH and therefore any increase in toxicity to Lemna minor. Received: 30 April 2005; Accepted: 23 June 2005.}, number={5}, journal={Coloration Technology}, author={Edwards, L. C. and Freeman, H. S.}, year={2005}, pages={271–274} }
 @article{umbuzeiro_freeman_warren_oliveira_terao_watanabe_claxton_2005, title={The contribution of azo dyes to the mutagenic activity of the Cristais River}, volume={60}, ISSN={["1879-1298"]}, DOI={10.1016/j.chemosphere.2004.11.100}, abstractNote={To verify whether dyes emitted within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the following mutagenic samples: the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water Treatment Plant (DWTP) located approximately 6 km from the industrial discharge. Considering that 20% of the dyes used for coloring activities might be lost to wastewaters and knowing that several dyes have mutagenic activity, we decided to analyze the samples for the presence of dyes. Thin layer chromatographic analysis indicated the presence of three prevalent dyes in all samples, except for the drinking water. This combination of dyes corresponded to a commercial product used by the industry, and it tested positive in the Salmonella assay. The structures of the dye components were determined using proton magnetic resonance and mass spectrometric (MS) methods, and the dyes were tested for mutagenicity. The blue component was identified as the C.I. Disperse Blue 373, the violet as C.I. Disperse Violet 93, and the orange as C.I. Disperse Orange 37. The dyes showed mutagenic responses of 6300, 4600, and 280 revertants/microg for YG1041 with S9 respectively. A bioassay-directed fractionation/chemical analysis showed that the C.I. Disperse Blue 373 contributed 55% of the mutagenic activity of the DWTP sludge. We showed that these dyes contributed to the mutagenic activity found in the Cristais River environmental samples analyzed and are indirectly affecting the quality of the related drinking water. Therefore, we believe that this type of discharge should be more thoroughly characterized chemically and toxicologically. Additionally, human and ecological risks associated with the release of dye processing plant effluents should be more fully investigated, especially where the resultant water is taken for human consumption.}, number={1}, journal={CHEMOSPHERE}, author={Umbuzeiro, GDA and Freeman, HS and Warren, SH and Oliveira, DP and Terao, Y and Watanabe, T and Claxton, LD}, year={2005}, month={Jun}, pages={55–64} }
 @inbook{freeman_smith_2005, title={Water and wastewater analysis}, ISBN={9780849334832}, DOI={10.1533/9781845690694.242}, booktitle={Chemical testing of textiles}, publisher={Boca Raton: Crc Press}, author={Freeman, H. and Smith, C.B.}, year={2005}, pages={242–269} }
 @article{freeman_2004, title={Color yes, toxicity no: Systematic approaches to meeting this challenge}, volume={4}, number={12}, journal={AATCC Review}, author={Freeman, H. S.}, year={2004}, pages={16–21} }
 @inproceedings{freeman_szymczyk_el-shafei_2004, title={Design, synthesis, and characterization of new iron-complexed azo dyes}, ISBN={9788085119015}, booktitle={Colorchem '04: proceedings : 23-27 May 2004, Hotel Harmony, S?pindleru?v Mly?n, Czech Republic}, publisher={Pardubice: Vy?zkumny? u?stav organicky?ch synte?z}, author={Freeman, H.S. and Szymczyk, M. and El-Shafei, A.}, year={2004} }
 @article{edwards_freeman_claxton_2004, title={Developing azo and formazan dyes based on environmental considerations: Salmonella mutagenicity}, volume={546}, ISSN={["1873-135X"]}, DOI={10.1016/j.mrfmmm.2003.10.002}, abstractNote={In previous papers, the synthesis and chemical properties of iron-complexed azo and formazan dyes were reported. It was shown that in certain cases iron could be substituted for the traditionally used metals such as chromium and cobalt, without having an adverse effect on dye stability. While these results suggested that the iron analogs were potential replacements for the commercially used chromium and cobalt prototypes, characterization of potentially adverse environmental effects of the new dyes was deemed an essential step in their further development. The present paper provides results from using the Salmonella/mammalian microsome assay to determine the mutagenicity of some important commercial metal complexed dyes, their unmetallized forms, and the corresponding iron-complexed analogs. The study compared the mutagenic properties of six unmetallized azo dyes, six commercial cobalt- or chromium-complexed azo dyes, six iron-complexed azo dyes, six unmetallized formazan dyes, and six iron-complexed formazan dyes. The results of this study suggest that the mutagenicity of the unmetallized dye precursors plays a role in determining the mutagenicity of the iron-complexes. For the monoazo dye containing a nitro group, metal complex formation using iron or chromium decreased or removed mutagenicity in TA100; however, little reduction in mutagenicity was noted in TA98. For the formazan dye containing a nitro group, metal-complex formation using iron increased mutagenicity. Results varied for metal-complexes of azo and formazan dyes without nitro groups, but in general, the metal-complexed dyes based on mutagenic ligands were also mutagenic, while those dyes based on nonmutagenic ligands were nonmutagenic.}, number={1-2}, journal={MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS}, author={Edwards, LC and Freeman, HS and Claxton, LD}, year={2004}, month={Feb}, pages={17–28} }
 @article{shaw_freeman_2004, title={Dyes from enzyme-mediated oxidation of aromatic amines}, volume={74}, ISSN={["1746-7748"]}, DOI={10.1177/004051750407400305}, abstractNote={ This paper characterizes reaction products from the oxidoreductase enzymatic conver sion of aromatic amines to dyes that have an affinity for wool fibers. The dyes are identified with the aid of mass spectrometry, FRIR, 1H-NMR, combustion analysis, and by comparison of experimental and calculated λmax data. The results of these analyses indicate that the dyes are binuclear and trinuclear aromatic compounds, depending on the number of available coupling sites in the precursor molecules and the number of reactants employed in the coupling step. Pathways associated with this enzyme-induced formation of dyes are proposed that involve a two-electron oxidation of 1.4-diamines to electrophilic diimines. }, number={3}, journal={TEXTILE RESEARCH JOURNAL}, author={Shaw, SD and Freeman, HS}, year={2004}, month={Mar}, pages={215–222} }
 @article{freeman_szymczyk_2004, title={Metal-complexed dyes}, volume={34}, DOI={10.1111/j.1478-4408.2004.tb00151.x}, abstractNote={Review of Progress in Coloration and Related TopicsVolume 34, Issue 1 p. 39-57 Metal–complexed dyes Malgorzata Szymczyk, Malgorzata Szymczyk Malgorzata Szymczyk is a visiting assistant professor and Harold S freeman is Ciba professor of dyestuff chemistry at the Department of Textile Engineering. Chemistry and Science. North Carolina Slate University, Raleigh, North Carolina. USA (email: Harold_Freeman@ncsu.edu).Search for more papers by this authorHarold S Freeman, Harold S Freeman Malgorzata Szymczyk is a visiting assistant professor and Harold S freeman is Ciba professor of dyestuff chemistry at the Department of Textile Engineering. Chemistry and Science. North Carolina Slate University, Raleigh, North Carolina. USA (email: Harold_Freeman@ncsu.edu).Search for more papers by this author Malgorzata Szymczyk, Malgorzata Szymczyk Malgorzata Szymczyk is a visiting assistant professor and Harold S freeman is Ciba professor of dyestuff chemistry at the Department of Textile Engineering. Chemistry and Science. North Carolina Slate University, Raleigh, North Carolina. USA (email: Harold_Freeman@ncsu.edu).Search for more papers by this authorHarold S Freeman, Harold S Freeman Malgorzata Szymczyk is a visiting assistant professor and Harold S freeman is Ciba professor of dyestuff chemistry at the Department of Textile Engineering. Chemistry and Science. North Carolina Slate University, Raleigh, North Carolina. USA (email: Harold_Freeman@ncsu.edu).Search for more papers by this author First published: 23 October 2008 https://doi.org/10.1111/j.1478-4408.2004.tb00151.xCitations: 8 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume34, Issue1June 2004Pages 39-57 RelatedInformation}, journal={Review of Progress in Coloration and Related Topics}, author={Freeman, H.S. and Szymczyk, M.}, year={2004}, pages={39–57} }
 @article{el-shafei_hinks_boyle_freeman_2004, title={Non-mutagenic organic pigment intermediates. II. Isomorphous 2,2 '-dichloro-5,5 '-dipropoxybenzidine and 2,2 '-dimethyl-5,5 '-dipropoxybenzidine}, volume={60}, ISSN={["2053-2296"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-4444237632&partnerID=MN8TOARS}, DOI={10.1107/S0108270104014763}, abstractNote={The title compounds, C 18 H 22 Cl 2 N 2 O 2 and C 20 H 28 N 2 O 2 , respectively, are isomorphous. The molecules lie at general positions in the unit cell. In each structure, chemically equivalent but crystallographically inequivalent amine N atoms exhibit different degrees of pyramidalization. The structures exhibit weak N-H...N hydrogen bonding, which is influenced by the differences in hybridization around the amine N atoms. The torsion angles across the biphenyl linkage for the two compounds are 67.2 (2) and 68.3 (3)°.}, number={8}, journal={ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY}, author={El-Shafei, A and Hinks, D and Boyle, PD and Freeman, HS}, year={2004}, month={Aug}, pages={O569–O571} }
 @article{suwanruji_freeman_zhao_2004, title={Studies toward a universal dye for textile fibres}, volume={120}, DOI={10.1111/j.1478-4408.2004.tb00121.x}, abstractNote={A new organic dye was synthesised as part of an approach to producing a dye that could be applied to any of a variety of widely used fibre types. The dye synthesised is best described as a disperse‐reactive dye and was obtained from a sequence of reactions that used an acid yellow dye as a starting compound. Dichlorotriazine was used as the reactive group in the target dye and the chemical structures of the new dye and its precursors were confirmed using 1H NMR, mass spectrometry and FTIR analyses. In the neutral form, the dye was suitable for polyester, nylon and wool fibres. When the pH was adjusted to 9 it dyed cotton, albeit in a pastel shade only. By adding N, N‐dimethylethylenediamine to the dyebath, the dye could be applied to acrylic fabric at pH 5. The fastness of the dyed fibres was also evaluated.}, number={5}, journal={Coloration Technology}, author={Suwanruji, P. and Freeman, H. S. and Zhao, D. F.}, year={2004}, pages={220–225} }
 @article{freeman_berthelon_edwards_2004, title={Studies towards lightfast automotive dyes for polyester}, volume={3}, number={4}, journal={Journal of Textile and Apparel Technology and Management}, author={Freeman, H. S. and Berthelon, N. and Edwards, L. C.}, year={2004}, pages={14} }
 @article{yin_xiong_zhao_freeman_2004, title={Syntheses, mutagenicity and applied performance of 2,8-diamino-10-methoxy-5,10-dihydrophenophosphazine 10-oxide}, volume={62}, number={10}, journal={Acta Chimica Sinica}, author={Yin, Z. G. and Xiong, W. D. and Zhao, D. F. and Freeman, H. S.}, year={2004}, pages={986–991} }
 @article{pielesz_freeman_weselucha-birczynska_wysocki_wlochowicz_2003, title={Assessing secondary structure of a dyed wool fibre by means of FTIR and FTR spectroscopies}, volume={651}, ISSN={["0022-2860"]}, DOI={10.1016/s0022-2860(03)00210-2}, abstractNote={The paper describes changes in the structure of a wool fibre dyed with model azo dyes. These were direct dyes, non-genotoxic derivatives of carcinogenic benzidine, synthesized specially for the purpose of the experiment. The non-mutagenic benzidine derivatives were: 2,2′-dimethyl-5,5′-dipropoxybenzidine and 5,5′-dipropoxybenzidine. Using FTIR, changes in secondary structure of fibres were assessed in three measuring ranges: 3600–3000, 1700–1400 and 1000–1300 cm−1. The dyes were found to distinctively affect wave-number shifts of amide A, amide I bands and in the fingerprint area around 1050 cm−1. It seems that these three areas are related to the sites in which dyes bind with wool fibre keratin. In FTR spectra, the focus was on assessing the changes of peptide bond configuration in the area of amide I, disulfide area of cystine and the area of the interaction between dyes and wool fibre keratin, i.e. 1250–1600 cm−1. For analysis, three kinds of materials were selected: (1) raw wool fibres, (2) fibres subjected to deuteration and treated with formic acid, (3) wool fabric. Each of them was dyed with the model azo dyes. The results obtained by both spectroscopies allow for identifying the functional groups responsible for the binding of dyes with keratin fibre.}, journal={JOURNAL OF MOLECULAR STRUCTURE}, author={Pielesz, A and Freeman, HS and Weselucha-Birczynska, A and Wysocki, M and Wlochowicz, A}, year={2003}, month={Jun}, pages={405–418} }
 @article{freeman_pielesz_wysocki_weselucha-birczynska_wlochowicz_2003, title={Characterisation of direct dye interactions with cotton via IR and Raman spectroscopies}, volume={6}, number={4}, journal={Advances in Colour Science and Technology}, author={Freeman, H. S. and Pielesz, A. and Wysocki, M. and Weselucha-Birczynska, A. and Wlochowicz, A.}, year={2003}, pages={111–115} }
 @inbook{freeman_mock_2003, title={Dye application, manufacture of dye intermediates and dyes}, ISBN={9780306474118}, booktitle={Riegel's handbook of industrial chemistry (10th ed.)}, publisher={New York: Kluwer Academic/Plenum Publishers}, author={Freeman, H.S. and Mock, G.N.}, year={2003} }
 @article{bae_freeman_el-shafei_2003, title={Metallization of non-genotoxic direct dyes}, volume={57}, ISSN={["0143-7208"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037967378&partnerID=MN8TOARS}, DOI={10.1016/S0143-7208(02)00120-1}, abstractNote={Copper (II) salts were used as metallizing agents in the synthesis of new direct dyes for cotton. In this regard, direct dyes possessing ortho-propoxy, ortho′-hydroxy-substituted systems formed the corresponding dye–metal complexes. The complexes were characterized by neutron activation and spectrometric analyses and evaluated on cotton for color fastness.}, number={2}, journal={DYES AND PIGMENTS}, author={Bae, JS and Freeman, HS and El-Shafei, A}, year={2003}, month={May}, pages={121–129} }
 @article{el-shafei_boyle_hinks_freeman_2003, title={Non-mutagenic organic pigment intermediates. I. 3,3 '-Dipropoxybenzidine}, volume={59}, ISSN={["0108-2701"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-0037295760&partnerID=MN8TOARS}, DOI={10.1107/S0108270102021303}, abstractNote={Crystals of the title compound, C(18)H(24)N(2)O(2), were grown from ethanol by slow evaporation and the structure has been determined. The molecule resides on a crystallographic inversion center and the biphenyl moiety is essentially planar. The structure forms an infinite two-dimensional array of N-H.pi(arene) interactions parallel to the (101) direction.}, number={2}, journal={ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS}, author={El-Shafei, A and Boyle, PD and Hinks, D and Freeman, HS}, year={2003}, month={Feb}, pages={O71–O73} }
 @article{yin_jin_zhao_peng_freeman_2003, title={Studies on the synthesis and mutagenicity of 2,8-diamino-10- hydroxy-5-methyl-5,10-dihydrophenophosphazine-10-oxide}, volume={24}, number={7}, journal={Chemical Journal of Chinese Universities}, author={Yin, Z. G. and Jin, K. and Zhao, D. F. and Peng, Q. J. and Freeman, H. S.}, year={2003}, pages={1210–1215} }
 @article{hooker_hinks_freeman_2003, title={Synthesis, properties and application of four new 1: 2 aluminium-complexed azo dyes}, volume={119}, DOI={10.1111/j.1478-4408.2003.tb00150.x}, abstractNote={In view of the well‐known environmental concerns associated with the synthesis and application of certain metal‐complexed acid dyes, potentially less toxic analogues of four chromium and cobalt 1;2‐complexed azo dyes were synthesised by employing aluminium in lieu of chromium or cobalt. The aluminium‐complexed dyes produced brighter shades on nylon 6.6 and wool than the corresponding 1;2‐complexed dyes based on chromium, cobalt and iron. The lightfastness results of nylon 6.6 and wool dyed with the 1;2 aluminium‐complexed dyes were, in general, better than the unmetallised precursors, but inferior to the corresponding chromium, cobalt and iron dyes.}, number={1}, journal={Coloration Technology}, author={Hooker, J. and Hinks, D. and Freeman, H.}, year={2003}, pages={41–47} }
 @article{bae_freeman_2002, title={Copper salts in the post-metallization of non-genotoxic direct dyes}, volume={3}, ISSN={["1229-9197"]}, DOI={10.1007/BF02912659}, number={4}, journal={FIBERS AND POLYMERS}, author={Bae, JS and Freeman, HS}, year={2002}, month={Dec}, pages={147–152} }
 @article{bae_freeman_2002, title={Synthesis and evaluation of non-genotoxic direct dyes}, volume={3}, ISSN={["1229-9197"]}, DOI={10.1007/BF02912658}, number={4}, journal={FIBERS AND POLYMERS}, author={Bae, JS and Freeman, HS}, year={2002}, month={Dec}, pages={140–146} }
 @article{gong_gao_wang_zhao_freeman_2002, title={Trisazo direct black dyes based on nonmutagenic 3,3 '-disubstituted benzidines}, volume={53}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(02)00010-4}, abstractNote={Abstract Using 3,3′-di-n-propoxybenzidine, 3,3′-di-n-butoxybenzidine and 3,3′-di-(β-hydroxyethoxy)-benzidine as diazo components, and 2,4-diamino-n-propoxybenzene, 2,4-diamino-n-butoxybenzene and 2,4-diaminophenyl-β-hydroxyethyl ether as coupling components, a series of new black trisazo dyes were prepared as homologues of C.I. Direct Black 38. Assessment of the resultant dyes indicated that their color and the dyeing properties were comparable or slightly better than the properties of C.I. Direct Black 38.}, number={2}, journal={DYES AND PIGMENTS}, author={Gong, GL and Gao, X and Wang, JL and Zhao, DF and Freeman, HS}, year={2002}, month={May}, pages={109–117} }
 @article{freeman_bae_2001, title={Direct dyes from non-genotoxic diamines}, volume={1}, number={9}, journal={AATCC Review}, author={Freeman, H. and Bae, J-S.}, year={2001}, pages={67} }
 @article{bae_freeman_2001, title={Direct dyes from nongenotoxic diamines}, volume={1}, number={9}, journal={AATCC Review}, author={Bae, J. S. and Freeman, H. S.}, year={2001}, pages={67–70} }
 @article{el-shafei_hinks_freeman_lye_2001, title={Semi-empirical molecular orbital methods in the design of organic colorants}, volume={1}, number={12}, journal={AATCC Review}, author={El-Shafei, A. and Hinks, D. and Freeman, H. S. and Lye, J.}, year={2001}, pages={23–26} }
 @article{el-shafei_hinks_freeman_2001, title={Semi-empirical molecular orbital methods in the design of organic pigments}, volume={1}, number={12}, journal={AATCC Review}, author={El-Shafei, A. and Hinks, D. and Freeman, H. S.}, year={2001}, pages={23–26} }
 @article{hinks_freeman_arai_ando_2001, title={Synthesis and evaluation of organic pigments. 2. Studies of bisazomethine pigments based on planar nonmutagenic benzidine analogs}, volume={48}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(00)00087-5}, abstractNote={Abstract The synthesis, characterization, genotoxicity and light fastness of thio- and oxopyrimidine based bisazomethine pigments prepared from a series of nonmutagenic benzidine congeners is reported. Whereas bisazomethine pigments based on benzidine and 3,3′-dimethylbenzidine were mutagenic in both the Ames assay and the Prival modification of the Ames assay, incorporation of bulky (>C 2 ) alkyl and alkoxy groups in the 3,3′- positions of the benzidine moiety gave nonmutagenic bisazomethine pigments.}, number={1}, journal={DYES AND PIGMENTS}, author={Hinks, D and Freeman, KS and Arai, Y and Ando, H}, year={2001}, month={Jan}, pages={7–13} }
 @article{sokolowska_hinks_freeman_2001, title={Synthesis and evaluation of organic pigments. 3. Studies based on nonmutagenic twisted benzidines}, volume={48}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(00)00088-7}, abstractNote={Bis-chromophoric pigments prepared using nonmutagenic benzidine analogs with high dihedral angle across the biphenyl linkage are reported. The mutagenic properties of twisted bisazomethine, disazoacetoacetanilide, disazopyrazolone, disazobenzimidazolone and disazonaphthol pigments were established using the standard Ames Salmonella mammalian mutagenicity assay and the Prival modification. Results from these tests and from the evaluation of hue, color strength and photostability of the pigments prepared are reported. Some of the new pigments are potential viable alternatives to those derived from 3,3′-dichlorobenzidine and other genotoxic analogs of benzidine.}, number={1}, journal={DYES AND PIGMENTS}, author={Sokolowska, J and Hinks, D and Freeman, HS}, year={2001}, month={Jan}, pages={15–27} }
 @article{nakpathom_hinks_freeman_2001, title={Synthesis and evaluation of organic pigments. 4. New monoarylide and diarylide pigments}, volume={48}, ISSN={["1873-3743"]}, DOI={10.1016/s0143-7208(00)00089-9}, abstractNote={The synthesis, characterization and mutagenicity of a series of diarylide pigments prepared using highly twisted nonmutagenic 2,2′-dimethyl-5,5′-dipropoxybenzidine and 2,2′-dimethoxy-5,5′-dipropoxybenzidine, and their monoarylide counterparts are reported. Five pigments in which nitro groups were incorporated into either the 3- or 4- position of the acetoacetanilide coupling component were mutagenic in either the standard Salmonella mutagenicity assay (Ames test) or the Prival modification. The presence of 3-trifluoromethyl or 3-acetyl groups in the acetoacetanilide moiety led to nonmutagenic pigments. Despite the high dihedral angle across the biphenyl linkage, the λmax of the highly twisted diarylide pigments was significantly bathochromic relative to the corresponding monoarylide pigments.}, number={2}, journal={DYES AND PIGMENTS}, author={Nakpathom, M and Hinks, D and Freeman, HS}, year={2001}, month={Feb}, pages={93–106} }
 @book{freeman_peters_2000, title={Colorants for non-textile applications (1st ed.)}, ISBN={9780444828880}, DOI={10.1016/b978-0-444-82888-0.x5030-2}, abstractNote={Preface. Contributors. Printing and Imaging Technologies. Dyes for Ink Jet Printing (K. Carr). Thermal Transfer Printing (R. Bradbury). Dyes used in Photography (D. Waller et al.). FD&C and Medical Dyes. Color Additives for Foods, Drugs, and Cosmetics (J.F. Senackerib). Biomedical Application of Dyes (J.C.V. Pais de Moura). Functional Dyes Directed for Molecular Recognition: Chromogenic and Fluorescent Receptors (M. Inouye). Functional Materials. Laser Dyes: Structure and Spectroscopic Properties (T.G. Pavlopoulos). Multifunctional Dye Materials from New Dicyanopyrazine Chromophores (M. Matsuoka). Natural Color/Substrates. Natural Dyes (A.G. Puntener, U. Schlesinger). Synthetic Dyes for Human Hair (J.F. Corbett). Leather Dyes (A.G. Puntener). Structural Colors: Nano-optics in the Biological World (M. Srinivasarao). Index.}, publisher={New York: Elsevier}, author={Freeman, H.S. and Peters, A.T.}, year={2000}, pages={618} }
 @article{bello_shen_zhao_esancy_freeman_2000, title={Dyes based on 5,10-dihydrophenophosphazine. Part I: Disazo direct dyes}, volume={46}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(00)00044-9}, abstractNote={The synthesis of 2,8-diamino-5,10-dihydro-10-hydroxy-5-methylphenophosphazine 10-oxide as a possible replacement for the benzidine moiety in some disazo dyes and the use of this new diamine in the preparation of direct dyes were undertaken. The dyes obtained were applied to cotton to give purple to brilliant blue shades, and their structures were confirmed using negative ion electrospray mass spectrometry.}, number={3}, journal={DYES AND PIGMENTS}, author={Bello, KA and Shen, K and Zhao, D and Esancy, M and Freeman, H}, year={2000}, month={Sep}, pages={121–128} }
 @inbook{freeman_edwards_2000, title={Iron-complexed dyes: Colorants in green chemistry}, ISBN={9780841236783}, DOI={10.1021/bk-2000-0767.ch003}, abstractNote={Few textile and dye chemists would argue against the suggestion that textile wastewater containing toxic metal ions is a matter of considerable concern, and that a pollution prevention/source reduction approach to addressing this concern would be better than currently available waste treatment methods. With that point in mind, this chapter reflects work pertaining to the design and synthesis of metal-complexed dyes that contain potential replacements for metals now designated as "priority pollutants". The focus of the present report is on dye structures and their properties rather than the synthetic reactions employed. The goal of this research was the development of environmentally friendly metal complexed dyes. It was hoped that this would provide a green chemistry approach to minimizing the need to treat wastewater after the dyes are manufactured and/or applied to textiles, by eliminating the source of dye wastewater containing toxic metals. Our strategy was to identify alternative metal complexes that could replace chromium-, cobalt-, and copper-based synthetic dyes. This chapter includes discussion of the metals that are used to prepare metal-complexed dyes and the properties of key intermediates (ligands) from which the dyes are made.}, booktitle={Green chemical syntheses and processes}, publisher={Washington, DC: American Chemical Society}, author={Freeman, H.S. and Edwards, L.C.}, editor={P. T. Anastas, L. G. Heine and Williamson, T. C.Editors}, year={2000} }
 @article{lye_freeman_cox_2000, title={Molecular modeling of Congo Red analogues containing terphenyl and quarterphenyl moieties}, volume={47}, ISSN={["0143-7208"]}, DOI={10.1016/s0143-7208(00)00063-2}, abstractNote={The molecular structures of Congo Red and its terphenyl and quarterphenyl analogues were optimized by applying AM1 and PM3 semiempirical methods to partially optimized starting structures. It was necessary to carry out repetitive sequences consisting of manual adjustments to the input structures followed by optimization, in order to locate minima in each structure. In addition, the conformational space associated with rotations about the central phenyl rings was explored. AM1 predicted non-planar biphenyl, terphenyl, and quarterphenyl structures, whereas PM3 predicted planar structures. Both methods were in agreement with experimental data, in that the differences in the energy of planar and non-planar structures were small. PISYSTEM predicted that increasing the number of central phenyl rings in Congo Red would have a hypsochromic and hyperchromic effect on the absorption maximum.}, number={1-2}, journal={DYES AND PIGMENTS}, author={Lye, J and Freeman, HS and Cox, RD}, year={2000}, pages={53–64} }
 @article{bhat_freeman_velga_sztandera_trachtman_bock_2000, title={Monomethoxy-4-aminoazobenzenes: a computational study}, volume={46}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(00)00042-5}, abstractNote={Abstract The structural and electronic properties of the positional isomers of monomethoxy-4-aminoazobenzene (n-OMe-AAB) have been investigated using density functional theory with a basis set that includes polarization functions on all the atoms. These azo dyes are of interest because their carcinogenic activities depend dramatically on the position (n) of the methoxy group, e.g. 3-OMe-AAB is a potent hepatocarcinogen in the rat, whereas 2-OMe-AAB is a noncarcinogen. While it is generally believed that the various isomers of OMe-AAB require metabolic activation via N-hydroxylation prior to reaction with cellular macromolecules, we have shown that there are structural and electronic features present in these isomers that correlate with their carcinogenic behavior.}, number={2}, journal={DYES AND PIGMENTS}, author={Bhat, KL and Freeman, HS and Velga, J and Sztandera, L and Trachtman, M and Bock, CW}, year={2000}, month={Aug}, pages={109–119} }
 @article{reife_freeman_2000, title={Pollution prevention in the production of dyes and pigments}, volume={32}, number={1}, journal={Textile Chemist and Colorist & American Dyestuff Reporter}, author={Reife, A. and Freeman, H. S.}, year={2000}, pages={56–60} }
 @article{hinks_freeman_nakpathom_sokolowska_2000, title={Synthesis and evaluation of organic pigments and intermediates. 1. Nonmutagenic benzidine analogs}, volume={44}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(99)00078-9}, abstractNote={The design, synthesis, characterization, and genotoxicity of 4,4′ diaminobiphenyl (benzidine) analogs with substituents in the 3,3′ and/or 2,2′ positions are reported. Analogs containing bulky substituents in the 3,3′ positions significantly reduce or eliminate mutagenic activity, while substituents in the 2,2′-positions increase the dihedral angle across the biphenyl linkage––a property that can be utilized in the design of novel nonmutagenic colorants. 2,2′-Dimethylbenzidine was found to be mutagenic in both the standard Salmonella mammalian mutagenicity assay (Ames test) with metabolic acitivation and the preincubation assay protocol. 2,2′-Dichloro-5,5′-dipropoxybenzidine, 2,2′-dimethoxy-5,5′-dipropoxybenzidine and 2,2′-dimethyl-5,5′-dipropoxybenzidine were nonmutagenic in both assays. The corresponding bis-acetoacetamido derivatives of the latter two compounds were also nonmutagenic. Good yields with minimal purification were obtained for certain diamines, providing potentially useful nongenotoxic intermediates in the synthesis of bisazo and bisazomethine dyes and pigments.}, number={3}, journal={DYES AND PIGMENTS}, author={Hinks, D and Freeman, HS and Nakpathom, M and Sokolowska, J}, year={2000}, month={Feb}, pages={199–207} }
 @article{freeman_lye_1999, title={Azo and nitrodiphenylamine photochemistry}, volume={2}, journal={Advances in Colour Science and Technology}, author={Freeman, H. S. and Lye, J.}, year={1999} }
 @misc{freeman_sokolowska_1999, title={Developments in dyestuff chemistry}, DOI={10.1111/j.1478-4408.1999.tb00123.x}, abstractNote={Review of Progress in Coloration and Related TopicsVolume 29, Issue 1 p. 8-22 Developments in dyestuff chemistry Harold S Freeman, Harold S Freeman Ciba-Geigy professor at North Carolina State University, Raleigh, North Carolina, USA.Search for more papers by this authorJolanta Sokolowska, Jolanta Sokolowska Vice-dean at the Technical University of Lodz.Search for more papers by this author Harold S Freeman, Harold S Freeman Ciba-Geigy professor at North Carolina State University, Raleigh, North Carolina, USA.Search for more papers by this authorJolanta Sokolowska, Jolanta Sokolowska Vice-dean at the Technical University of Lodz.Search for more papers by this author First published: 23 October 2008 https://doi.org/10.1111/j.1478-4408.1999.tb00123.xCitations: 39AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. 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 @article{ukponmwan_odilora_offor_freeman_1999, title={Disperse Red 60 analogs}, volume={24}, number={4}, journal={Indian Journal of Fibre & Textile Research}, author={Ukponmwan, D. O. and Odilora, C. A. and Offor, M. N. and Freeman, H. S.}, year={1999}, pages={297–302} }
 @article{freeman_mason_lye_1999, title={Disperse dyes containing a built-in oxalanilide stabilizer}, volume={42}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(99)00009-1}, abstractNote={Monoazo and nitrodiphenylamine disperse dyes containing an oxalanilide photostabilizer have been synthesized and evaluated for lightfastness as potential automotive dyes. The results showed that the lightfastness of CI Disperse Red 167 could be appreciably enhanced, depending on the substituent employed in the oxalanilide moiety. While it was also possible to improve the lightfastness of CI Disperse Yellow 86, the resulting lightfastness was not as high as that observed when a hydroxybenzophenone stabilizer was incorporated. ©}, number={1}, journal={DYES AND PIGMENTS}, author={Freeman, HS and Mason, ME and Lye, J}, year={1999}, month={Apr}, pages={53–63} }
 @article{lye_freeman_hinks_1999, title={Molecular modeling in dye chemistry: Studies involving two disperse dyes}, volume={69}, ISSN={["0040-5175"]}, DOI={10.1177/004051759906900807}, abstractNote={ The equilibrium geometries of C.I. Disperse Yellow 86 and C.I. Disperse Red 167 are predicted using semi-empirical and mechanical methods. All semi-empirical geometry optimizations involve MNDO, MINDO/3, AM1. and PM3 Hamiltonians implemented in MOPAC, and CNDO and INDO Hamiltonians implemented in ZINDO for self-consistent field energy calculations. MOPAC optimizations use a Broyden-Fletcher-Goldfarb-Shanno func tion minimizer, while ZINDO optimizations employ a Newton-Raphson search minimiza tion technique. All semi-empirical optimizations are initiated from an identical starting structure that has been optimized with an augmented MM2 mechanical forcefield in conjunction with a conjugate gradient minimizer algorithm. When the predicted structures of the two disperse dyes are compared to x-ray crystal structures, PM3 and AM1 give the best correlations between predicted and experimental values for atomic and hydrogen bond lengths. MINDO/3 gives the closest predictions of the improper torsion angle asso ciated with aryl amino groups. PM3 and, to a lesser extent, AM1 tend to distort planar aryl amino nitrogen atoms. }, number={8}, journal={TEXTILE RESEARCH JOURNAL}, author={Lye, J and Freeman, HS and Hinks, D}, year={1999}, month={Aug}, pages={583–590} }
 @misc{freeman_hinks_sokolowska-gajda_1999, title={Organic pigments from twisted benzidines}, volume={5,965,717}, number={1999 Oct. 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Freeman, H. S. and Hinks, D. and Sokolowska-Gajda, J.}, year={1999} }
 @article{lye_freeman_mason_singh_1999, title={X-ray crystal structure of CI Disperse Yellow 86}, volume={42}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(99)00015-7}, abstractNote={In conjunction with studies pertaining to the design of lightfast dyes for PET, the X-ray crystal structure of C.I. Disperse Yellow 86 has been solved to R=0.067 using 1999 independent reflections of MoKα radiation, collected by the ω-scan method at a variable speed. Results showed that C.I. Disperse Yellow 86 is non-planar, with a dihedral angle of 35.3° between the phenyl rings. In addition, the ortho-nitroanilino moiety of this dye is planar, due to a hydrogen bond between the nitro group and the adjacent amino hydrogen atom. ©}, number={1}, journal={DYES AND PIGMENTS}, author={Lye, J and Freeman, HS and Mason, ME and Singh, P}, year={1999}, month={Apr}, pages={107–111} }
 @inbook{freeman_reife_betowski_1998, title={Dyes and pigments, environmental chemistry}, ISBN={9780471117087}, booktitle={Encyclopedia of environmental analysis and remediation}, publisher={New York: Wiley}, author={Freeman, H.S. and Reife, A. and Betowski, D.}, year={1998} }
 @article{sokolowska-gajda_hinks_haney_freeman_tanaka_1998, title={Field desorption mass spectral analysis of some nonmutagenic benzidine-based pigments}, volume={39}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(97)00116-2}, abstractNote={This paper is concerned with field desorption mass spectral (FDMS) analysis of novel disazomethine, disazoacetoacetanilide (diarylide) and disazopyrazolone pigments containing nonmutagenic benzidine homologs. The FD spectra of the aforementioned types of pigments are characterized by intense parent ion peaks [M+.] and relatively intense [M+]/2 daughter ions, a pattern which serves as a fingerprint for these molecular structures.}, number={3}, journal={DYES AND PIGMENTS}, author={Sokolowska-Gajda, J and Hinks, D and Haney, CA and Freeman, HS and Tanaka, M}, year={1998}, month={Oct}, pages={159–171} }
 @article{bardole_freeman_reife_1998, title={Iron salts in the post-metallization of mordant dyes}, volume={68}, ISSN={["0040-5175"]}, DOI={10.1177/004051759806800210}, abstractNote={ Iron (II) and iron (III) salts are used as mordanting agents in lieu of chromium ions, as a source reduction approach to eliminating chromium in dye effluents following the post-metallization of acid mordant dyes. Specifically, wool fabric is dyed with Mordant Yellow 8, Yellow 30, Orange 3, Orange 6, Red 7. Red 19, Blue 1, Blue 9, Blue 13, Brown 40, Black 1, and Black 11, then treated with iron salts. The complexes are characterized by negative ion fast-atom bombardment mass spectrometry and absorp tion spectrophotometry, and the after-treated fabrics are evaluated for lightfastness and washfastness. Mordant dyes possessing either ortho, ortho'-bis(hydroxy)- phenylazopyrazole or ortho-hydroxy-phenylazonaphthol substituted chromophoric sys tems form the corresponding 1:2 metal : dye complex and undergo significant improve ments in lightfastness and washfastness following metallization. }, number={2}, journal={TEXTILE RESEARCH JOURNAL}, author={Bardole, HA and Freeman, HS and Reife, A}, year={1998}, month={Feb}, pages={141–149} }
 @inbook{freeman_lye_hinks_1997, title={Computational chemistry applied to synthetic dyes}, ISBN={9789810232207}, booktitle={Computational chemistry and chemical engineering: proceedings of the Third UNAM-CRAY Supercomputing Conference: Universidad Nacional Auto?noma de Me?xico, 13-16 August 1996}, publisher={River Edge, NJ: World Scientific}, author={Freeman, H.S. and Lye, J. and Hinks, D.}, year={1997} }
 @misc{freeman_sokolowska-gajda_reife_1997, title={Iron-complexed formazan dyes for polyamide and protein substrates}, volume={5,677,434}, number={1997 Oct. 14}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Freeman, H. S. and Sokolowska-Gajda, J. and Reife, A.}, year={1997} }
 @article{reife_weber_freeman_1997, title={Iron: Producing more than rust in our environment}, volume={27}, number={10}, journal={Chemtech}, author={Reife, A. and Weber, E. and Freeman, H. S.}, year={1997}, pages={17–25} }
 @article{freeman_mcintosh_singh_1997, title={X-ray crystal structure of disazo dyes .1. CI Disperse Orange 29}, volume={35}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(96)00095-2}, abstractNote={Crystals of C.I. Disperse Orange 29, a disazo dye, were grown from a methanol solution and the X-ray structure was solved from 2484 independent reflections to R = 0.0497. Results showed that the crystal examined exists in the triclinic space group P1. Interestingly, the structure generated possessed a syn conformation, unlike 4-phenylazoazobenzene which is known to exist in the anti conformation.}, number={1}, journal={DYES AND PIGMENTS}, author={Freeman, HS and McIntosh, SA and Singh, P}, year={1997}, month={Sep}, pages={11–21} }
 @article{freeman_mcintosh_singh_1997, title={X-ray crystal structure of disazo dyes .2. Derivatives of CI Disperse Yellow 23 and CI Disperse Orange 29}, volume={35}, ISSN={["0143-7208"]}, DOI={10.1016/S0143-7208(96)00096-4}, abstractNote={Crystals of the 2,6-dichlorobenzoyl ester of C.I. Disperse Yellow 23 and C.I. Disperse Orange 29 were grown from chloroform, and cell dimensions were determined by a least-squares fit. Crystals of both esters were found to exist in the monoclinic space group P21/C. The structures of these dyes possessed the anti conformation, unlike that of underivatized C.I. Disperse Orange 29, but the same as that reported for 4-phenylazoazobenzene.}, number={2}, journal={DYES AND PIGMENTS}, author={Freeman, HS and McIntosh, SA and Singh, P}, year={1997}, month={Oct}, pages={149–164} }
 @inbook{freeman_reife_1996, title={Carbon adsorption}, ISBN={9780471589273}, booktitle={Environmental chemistry of dyes and pigments}, publisher={New York: Wiley}, author={Freeman, H.S. and Reife, A.}, editor={A. Reife and Freeman, H S.Editors}, year={1996}, pages={3–31} }
 @inbook{sokolowska-gajda_freeman_reife_1996, title={Chemical removal of phosphate ions from disperse dye filtrates}, ISBN={9780471589273}, booktitle={Environmental chemistry of dyes and pigments}, publisher={New York: Wiley}, author={Sokolowska-Gajda, J. and Freeman, H.S. and Reife, A.}, editor={A. Reife and Freeman, H S.Editors}, year={1996}, pages={239–251} }
 @book{freeman_reife_1996, title={Environmental chemistry of dyes and pigments}, ISBN={9780471589273}, publisher={New York: Wiley}, author={Freeman, H.S. and Reife, A.}, year={1996}, pages={329} }
 @inbook{freeman_hinks_esancy_1996, title={Genotoxicity of azo dyes: Bases and implications}, ISBN={9780751402100}, DOI={10.1007/978-94-009-0091-2_7}, booktitle={Physico-chemical principles of color chemistry}, publisher={New York: Blackie Academic & Professional}, author={Freeman, H.S. and Hinks, D. and Esancy, J.}, editor={A.T. Peters and Freeman, H.S.Editors}, year={1996} }
 @book{freeman_peters_1996, title={Physico-chemical principles of color chemistry (1st ed.)}, ISBN={9780751402100}, DOI={10.1007/978-94-009-0091-2}, publisher={London : Blackie Academic & Professional}, author={Freeman, H.S. and Peters, A.T.}, year={1996}, pages={299} }
 @article{sokolowskagajda_freeman_reife_1996, title={Synthetic dyes based on environmental considerations .2. Iron complexed formazan dyes}, volume={30}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(95)00048-8}, abstractNote={This paper is concerned with the synthesis and evaluation of some 1:2 iron complexed formazan dyes for use on wool and nylon. The chemical structures of these new dyes were confirmed with the aid of negative ion FAB mass spectrometry, a technique which also proved instrumental in establishing the nature of the products obtained when unsymmetrical 1:2 iron complexed formazan dyes were synthetic targets. It is clear from the fastness properties obtained that certain of the title compounds could have utility in applications requiring high hightfastness.}, number={1}, journal={DYES AND PIGMENTS}, author={SokolowskaGajda, J and Freeman, HS and Reife, A}, year={1996}, pages={1–20} }
 @inproceedings{freeman_cleveland_sokolowska-gajda_reife_1995, title={A new look at iron complexed dyes}, booktitle={Book of papers: 1995 International Conference & Exhibition, October 8-11, Atlanta, Ga}, publisher={Research Triangle Park, N.C.: American Association of Textile Chemists and Colorists}, author={Freeman, H.S. and Cleveland, L.G. and Sokolowska-Gajda, J. and Reife, A.}, year={1995}, pages={397–405} }
 @inbook{hinks_lye_freeman_1995, title={Computer-aided dyestuff design}, booktitle={Annual international conference and exhibition of AATCC}, publisher={RTP, NC:  American Association of Textile Chemists and Colorists}, author={Hinks, D. and Lye, J. and Freeman, H.S.}, year={1995} }
 @article{kim s.d._freeman_1995, title={Effect of chemical structure on molecular motion of spin probes doped in nylon 6 film}, volume={32}, number={6}, journal={Journal of the Korean Fiber Society}, author={Kim S.D. and Freeman, H.S.}, year={1995}, pages={554} }
 @book{freeman_peters_1995, title={Modern colourants: Syntheses and structure}, ISBN={9780751402094}, DOI={10.1007/978-94-011-1356-4}, publisher={London : Blackie Academic & Professional}, author={Freeman, H.S. and Peters, A.T.}, year={1995} }
 @article{sokolowska-gajda_freeman_reife_1995, title={Synthesizing premetallized acid dyes based on environmental considerations}, volume={27}, number={2}, journal={Textile Chemist and Colorist}, author={Sokolowska-Gajda, J. and Freeman, H. S. and Reife, A.}, year={1995}, pages={13} }
 @misc{freeman_reife_sokalawska-gajda_1994, title={Environmentally friendly method for producing lightfast black shades on natural and synthetic substrates}, volume={5,376,151}, number={1994 Dec. 27}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Freeman, H. S. and Reife, A. and Sokalawska-Gajda, J.}, year={1994} }
 @article{freeman_mcintosh_1994, title={IRRADIATION OF CI DISPERSE YELLOW-23 AND DISPERSE ORANGE-29 IN AN ESTER ENVIRONMENT}, volume={64}, ISSN={["0040-5175"]}, DOI={10.1177/004051759406400601}, abstractNote={ The title compounds, both disazo dyes, were found to undergo photoisomerism in dimethylphthalate solution and in films cast from a mixture of dye and cellulose acetate. Light-induced isomerism did not occur, however, in PET film that had been extruded, oriented, and dyed with the same two colorants. The prolonged irradiation of disperse yellow 23 in either solution or a polymer matrix produced azobenzene and some mono-substituted azobenzenes. Disperse orange 29 underwent photodegradation to produce a mixture of disubstituted monoazobenzenes, a partially reduced disazo- benzene, and para-nitroaniline. }, number={6}, journal={TEXTILE RESEARCH JOURNAL}, author={FREEMAN, HS and MCINTOSH, SA}, year={1994}, month={Jun}, pages={309–315} }
 @article{sokolowskagajda_freeman_reife_1994, title={SYNTHETIC DYES BASED ON ENVIRONMENTAL CONSIDERATIONS .1. IRON COMPLEXES FOR PROTEIN AND POLYAMIDE FIBERS}, volume={64}, ISSN={["0040-5175"]}, DOI={10.1177/004051759406400704}, abstractNote={ We have described the synthesis of some novel 1:2 Fe complexed azo dyes and compared their properties with 1:2 Cr and 1:2 Co commercial analogs. We also report the interesting FAB mass spectroscopy analysis of 1:2 metallized azo dyes resulting in the formation of 1:1 complexed dyes and their unmetallized precursors. Results from light- and rubbing-fastness evaluations of these 1:2 Fe metallized dyes show the black dyes to be strong candidates for use on wool and nylon in applications requiring high lightfastness. }, number={7}, journal={TEXTILE RESEARCH JOURNAL}, author={SOKOLOWSKAGAJDA, J and FREEMAN, HS and REIFE, A}, year={1994}, month={Jul}, pages={388–396} }
 @misc{mcdermed_tadepalli_chang_hurley_freeman_1993, title={Anti-hypertensive sulfonanilides}, volume={5,194,450}, number={1993 Mar. 16}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={McDermed, J. D. and Tadepalli, A. S. and Chang, V. H. and Hurley, K. P. and Freeman, H. S.}, year={1993} }
 @article{voyksner_straub_keever_freeman_hsu_1993, title={DETERMINATION OF AROMATIC-AMINES ORIGINATING FROM AZO DYES BY CHEMICAL-REDUCTION COMBINED WITH LIQUID-CHROMATOGRAPHY MASS-SPECTROMETRY}, volume={27}, ISSN={["0013-936X"]}, DOI={10.1021/es00045a025}, abstractNote={Procedures were evaluated for the reductive cleavage of 16 commercial azo dyes using sodium hydrosulfite and tin(II) chloride. Identification of the reduction product were mainly based upon mass spectra obtained by particle beam high-performance liquid chromatography/mass spectrometry (HPLC/MS). Standards of the formed reduction products, when available, were employed to confirm identities. The chemical reduction method resulted in nearlycomplete reduction of the azo bond to form aromatic amines . Overall, tin chloride was the more powerful reducing agent, yielding a greater number of products. The analysis of reduced industrial waste sludge extracts indicated the presence of identifiable aromatic amines which originated from the reduction of unknown dye components}, number={8}, journal={ENVIRONMENTAL SCIENCE & TECHNOLOGY}, author={VOYKSNER, RD and STRAUB, R and KEEVER, JT and FREEMAN, HS and HSU, WN}, year={1993}, month={Aug}, pages={1665–1672} }
 @inproceedings{freeman_sokolowska-gajda_reife_1993, title={Premetallized acid dyes based on environmental considerations}, booktitle={Book of Papers, American Association of Textile Chemists and Colorists. International Conference & Exhibition}, author={Freeman, H.S. and Sokolowska-Gajda, J. and Reife, A.}, year={1993}, pages={254–259} }
 @article{sokolowskagajda_freeman_1992, title={A NEW MEDIUM FOR THE DIAZOTIZATION OF 2-AMINO-6-NITROBENZOTHIAZOLE AND 2-AMINOBENZOTHIAZOLE}, volume={20}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(92)85006-8}, abstractNote={Abstract To identify a useful alternative to H 3 PO 4 as a medium for diazotizing heteroaromatic amines a number of organic acids having a similar ionization constant (K 1 ) were examined. It was found that dichloroacetic acid is an effective solvent for both the diazotization of the title compounds and the synthesis of important commercial disperse dyes based on these amines. Dyes such as C.I. Disperse Red 177 and Disperse Violet 52 were readily obtained in 85–90% yield and very pure form.}, number={2}, journal={DYES AND PIGMENTS}, author={SOKOLOWSKAGAJDA, J and FREEMAN, HS}, year={1992}, pages={137–145} }
 @article{freeman_posey_1992, title={AN APPROACH TO THE DESIGN OF LIGHTFAST DISPERSE DYES - ANALOGS OF DISPERSE YELLOW-42}, volume={20}, ISSN={["1873-3743"]}, DOI={10.1016/0143-7208(92)80044-N}, abstractNote={The effects of incorporating a photostabilizer moiety into the aromatic rings of Disperse Yellow 42 have been investigated. The results of this study indicate that both the ring into which the stabilizer residue is placed and the actual type of stabilizer group employed influence the lightfastness of the dyes developed. It has also been shown that the incorporation of a photostabilizer group into the backbone of Disperse Yellow 42 can lead to dyes superior in lightfastness to a physical mixture of Yellow 42 and commercial photostabilizer.}, number={3}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and POSEY, JC}, year={1992}, pages={171–195} }
 @article{freeman_posey_1992, title={ANALOGS OF DISPERSE RED-167 CONTAINING A BUILT-IN PHOTOSTABILISER MOIETY}, volume={20}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(92)80043-M}, abstractNote={The effects of incorporating a benzophenone stabilizer into the structure of Disperse Red 167 have been investigated. In this study, four different substituents in the parent dye structure were substituted sequentially to build the desired stabilizer moiety into the backbone of the prototype dye. Although the lightfastness of the dyes prepared was not superior to that of the parent dye, each possessed better sublimation fastness than the prototype and served as a useful probe of the requirements for high light-fastness on polyester. The structure of each new compound was confirmed by [1H] NMR, elemental analysis, and mass spectrometry. In addition, the detailed structure of one of the analogs was determined from X-ray diffractometer data.}, number={3}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and POSEY, JC}, year={1992}, pages={147–169} }
 @article{rucker_freeman_hsu_1992, title={Evaluation of factors contributing to the light-induced yellowing of white-washed denim. part I: Identification of extractable organics and metal ions}, volume={24}, number={9}, journal={Textile Chemist and Colorist}, author={Rucker, J. W. and Freeman, H. S. and Hsu, W. N.}, year={1992}, pages={66} }
 @article{rucker_freeman_hsu_1992, title={Evaluation of factors contributing to the light-induced yellowing of white-washed denim. part II: Effects of various treatments on metal content and photo-yellowing}, volume={24}, number={10}, journal={Textile Chemist and Colorist}, author={Rucker, J. W. and Freeman, H. S. and Hsu, W. N.}, year={1992}, pages={21} }
 @article{freeman_posey_singh_1992, title={X-RAY CRYSTAL-STRUCTURE OF DISPERSE RED-167}, volume={20}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(92)87027-X}, abstractNote={X-ray diffractometer data have been used to determine the crystal structure of CI Disperse Red 167, an important automotive disperse dye. The structure was solved by direct methods and refined by least squares to R = 0.0442 for 1115 independent reflections. This monoazo dye possesses a planar azobenzene skeleton, as the dihedral angle between the planes made by the two aromatic rings is 1.5°. The non-bonding distance between the hydrogen atom of the acetamido group and azo nitrogen N(1) is well within the expected distance for intramolecular hydrogen bonding. Interestingly, the chloro and acetamido groups lie on the same side of the azo bond, and each unit cell of this dye contains 8 molecules.}, number={4}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and POSEY, JC and SINGH, P}, year={1992}, pages={279–289} }
 @article{freeman_kim_gilbert_mcgregor_1991, title={ARYLAZO DYES CONTAINING A BUILT-IN HINDERED-AMINE MOIETY}, volume={17}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(91)87023-G}, abstractNote={This paper describes the synthesis, spectral properties, and photolytic behavior of some 5-arylazo-6-hydroxy-y-carbolines. Like 1-arylazo-2-naphthols, these novel dyes exist primarily in the hydrazone form. Interestingly, however, the arylazo-γ-carboline dyes are significantly more light-stable in a polymer matrix than their 1-arylazo-2-naphthol counterparts. This suggests that the use of a built-in hindered-amine residue is an effective way to inhibit the lightinduced oxidation of arylhydrazone-type dyes. The preparation of novel nitroxide derivatives of the arylazo-γ-carbolines for electron spin resonance spin-probe studies is also described.}, number={2}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and KIM, SD and GILBERT, RD and MCGREGOR, R}, year={1991}, pages={83–100} }
 @inbook{freeman_esancy_claxton_1991, title={An approach to the design and synthesis of non-mutagenic dyes: Analogs of the mutagen 4-amino-3-methoxyazobenzene - the design and synthesis of organic dyes and pigments}, ISBN={9781851665778}, booktitle={Colour chemistry: the design and synthesis of organic dyes and pigments}, publisher={New York: Elsevier Applied Science}, author={Freeman, H.S. and Esancy, J.F. and Claxton, L.D.}, editor={A.T. Peters and Freeman, H.S.Editors}, year={1991} }
 @article{freeman_esancy_claxton_esancy_1991, title={Color, yes; cancer, no}, volume={21}, number={7}, journal={Chemtech}, author={Freeman, H. S. and Esancy, J. F. and Claxton, L. D. and Esancy, M. K.}, year={1991}, pages={438} }
 @book{freeman_peters_1991, title={Colour chemistry: The design and synthesis of organic dyes and pigments}, ISBN={9781851665778}, publisher={New York: Elsevier Applied Science}, author={Freeman, H.S. and Peters, A.T.}, year={1991} }
 @inproceedings{design and synthesis of lightfast disperse dyes_1991, booktitle={Book of papers: 1991 international Conference & Exhibition, October 8-11, Radisson Plaza Hotel, Charlotte, N.C.}, publisher={Research Triangle Park, N.C.: American Association of Textile Chemists and Colorists}, year={1991}, pages={114–121} }
 @article{freeman_hao_sokolowska-gajda_vanbreemen_1991, title={Matrix selection in the FAB mass spectral analysis of synthetic dyes}, volume={16}, number={4}, journal={Dyes and Pigments}, author={Freeman, H. S. and Hao, Z. and Sokolowska-Gajda, J. and VanBreemen, R. B.}, year={1991}, pages={317} }
 @article{mcintosh_freeman_singh_1991, title={X-RAY CRYSTAL-STRUCTURE OF THE DYE 4-(N,N-BIS-(BETA-HYDROXYETHYL) AMINO) AZOBENZENE}, volume={17}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(91)85023-2}, abstractNote={The crystal structure of 4-(N,N-bis-(β-hydroxyethyl)amino)azobenzene was determined through the use of X-ray diffractometer data. The structure was solved via direct methods and refined by least squares to R = 0.0594 for a data set consisting of 1610 unique reflections. The azobenzene skeleton of the dye is essentially planar, with a dihedral angle of 10.3° between the planes defined by the two aromatic rings. The geometry about the azo linkage, and some key bond lengths of this dye, are compared to the corresponding values for some previously reported azobenzenes.}, number={1}, journal={DYES AND PIGMENTS}, author={MCINTOSH, SA and FREEMAN, HS and SINGH, P}, year={1991}, pages={1–10} }
 @article{freeman_esancy_claxton_1990, title={AN APPROACH TO THE DESIGN OF NONMUTAGENIC AZO DYES - ANALOGS OF THE MUTAGEN CI DIRECT BLACK 17}, volume={13}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(90)80013-F}, abstractNote={The effect on mutagenicity caused by incorporating an alkoxy substituent into the structure of a disazo hydrophilic dye has been investigated. The results of this study indicate that while bulky alkoxy groups are useful in lowering the mutagenicity of certain analogs of CI Direct Black 17, the decrease observed is less than that noted for a series of monoazo disperse dyes. The color and fastness properties of these novel disazo dyes are also described.}, number={1}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and ESANCY, JF and CLAXTON, LD}, year={1990}, pages={55–70} }
 @article{ukponmwan_freeman_1990, title={CHARACTERIZATION OF THE PRODUCTS DERIVED FROM THE NITRATION OF 1,5-DIHYDROXYANTHRAQUINONE (ANTHRARUFIN) AND 1,8-DIHYDROXYANTHRAQUINONE (CHRYSAZIN)}, volume={12}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(90)80006-B}, abstractNote={When 1,5-dihydroxyanthraquinone (Anthrarufin) and 1,8-dihydroxyanthraquinone (Chrysazin) were nitrated using a mixture of concentrated sulfuric and nitric acids in the presence of boric acid at 10–25° C, three major products formed in each reaction. The products were separated by low-pressure column chromatography and identified by 1H-NMR and mass spectrometric analyses in tandem. The products identified result from the mono-, di- and tetra-nitration of these dihydroxyanthraquinones.}, number={2}, journal={DYES AND PIGMENTS}, author={UKPONMWAN, DO and FREEMAN, HS}, year={1990}, pages={145–155} }
 @article{freeman_van breeman_esancy_hao_ukponmwan_hsu_1990, title={Fast atom bombardment and desorption chemical ionization mass spectrometry in the analysis of involatile textile dyes}, volume={22}, number={5}, journal={Textile Chemist and Colorist}, author={Freeman, H. S. and Van Breeman, R. B. and Esancy, J. F. and Hao, Z. and Ukponmwan, D. O. and Hsu, W. N.}, year={1990}, pages={23} }
 @misc{freeman_1990, title={Method for producing lightfast disperse dyestuffs containing a build-in photostabilizer [molecule] compound}, volume={4,902,787}, number={1990 Feb. 20}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Freeman, H. S.}, year={1990} }
 @article{freeman_sokolowskagajda_1990, title={PHOTODEGRADATION OF CI ACID ORANGE-60 AND CI ACID GREEN-25 IN AN AMIDE ENVIRONMENT}, volume={60}, ISSN={["0040-5175"]}, DOI={10.1177/004051759006000405}, abstractNote={Photodegradation, in solution and in nylon 66 fiber, of two automotive acid dyes (CI acid orange 60 and CI acid green 25) for nylon carpet has been investigated. Photofading in solution was done in dimethylformamide (DMF) with the aid of a 254-nm light source, and the work in nylon fiber used the xenon arc light of an Atlas CI 65 weatherometer. The results show that these dyes fade via a photoreduction process under both sets of conditions, and they suggest that DMF is a suitable model for nylon in characterizing the photodegradation of acid dyes. The structures of the degradation products of the two dyes were determined with the aid of fast atom bom bardment and desorption chemical ionization mass spectrometry and by HPLC and TLC comparisons with authentic samples.}, number={4}, journal={TEXTILE RESEARCH JOURNAL}, author={FREEMAN, HS and SOKOLOWSKAGAJDA, J}, year={1990}, month={Apr}, pages={221–227} }
 @article{freeman_hao_mcintosh_posey_hsu_1990, title={PURIFICATION PROCEDURES FOR SYNTHETIC DYES .4. FLASH CHROMATOGRAPHY}, volume={12}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(90)85015-G}, abstractNote={The suitability of flash chromatography for the purification of synthetic dyestuffs has been investigated. The results of this study indicate that this technique offers a rapid procedure for the generation of gram quantities of a disperse dye, provided the dye to be purified is reasonably soluble in ordinary organic solvents such as toluene, ethyl acetate, or hexane. It is also apparent that the water-containing eluents commonly used to develop hydrophilic dyestuffs do not give satisfactory results when silica gel is used, due to strong eluent-adsorbent interactions. As a consequence, the purification of hydrophilic dyes required deactivated alumina. The speed with which a purification is accomplished by flash chromatography often offsets the higher amount of solvent required compared with the amounts used in dry column chromatography and countercurrent chromatography.}, number={3}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and HAO, Z and MCINTOSH, SA and POSEY, JC and HSU, WN}, year={1990}, pages={233–242} }
 @article{freeman_mcintosh_1990, title={Some interesting substituent effects in merocyanine dyes}, volume={27}, number={3}, journal={Education in Chemistry}, author={Freeman, H.S. and McIntosh, S.A.}, year={1990}, pages={79} }
 @inbook{claxton_walsh_esancy_freeman_1990, title={Structure activity analysis of azo dyes and related  compounds}, ISBN={9780471567929}, booktitle={Mutation and the environment: proceedings of the Fifth International Conference on Environmental Mutagens, held in Cleveland, Ohio, July 10-15, 1989 (Pt. B)}, publisher={New York: Wiley-Liss}, author={Claxton, L.D. and Walsh, D.B. and Esancy, J.F. and Freeman, H.S.}, editor={M. L. Mendelsohn and Albertini, R. J.Editors}, year={1990} }
 @misc{esancy_freeman_claxton_1990, title={THE EFFECT OF ALKOXY SUBSTITUENTS ON THE MUTAGENICITY OF SOME AMINOAZOBENZENE DYES AND THEIR REDUCTIVE-CLEAVAGE PRODUCTS}, volume={238}, ISSN={["0921-8262"]}, DOI={10.1016/0165-1110(90)90036-B}, abstractNote={15 aminoazobenzene dyes and 7 of their reductive-cleavage products were examined in the Salmonella/microsome assay with strains TA98, TA100, TA1535, TA1537 and TA1538. Dyes tested included 5 derivatives of 4-aminoazobenzene with different alkoxy substituents (-OCH3, -OCH2CH3, -OCH2CH2 CH3, -OCH2CH2CH2CH3 or -OCH2CH2OH) in the 8-position as well as the corresponding derivatives of 4-[(4-aminophenyl)azo]-N,N-diethylaniline and 4-[(4-aminophenyl)azo]-N,N-bis(2-hydroxyethyl)aniline. In general, as the size of the substituent ortho to the primary amino group of the dyes was increased, the mutagenicity decreased. A similar trend was observed for the reductive-cleavage products. The results from the latter aspect of this study suggest that the mutagenicity of aminoazobenzene dyes can not be accounted for solely from the properties of their reductive-cleavage products.}, number={1}, journal={MUTATION RESEARCH}, author={ESANCY, JF and FREEMAN, HS and CLAXTON, LD}, year={1990}, month={Jan}, pages={1–22} }
 @misc{esancy_freeman_claxton_1990, title={THE EFFECT OF ALKOXY SUBSTITUENTS ON THE MUTAGENICITY OF SOME PHENYLENEDIAMINE-BASED DISAZO DYES}, volume={238}, ISSN={["0921-8262"]}, DOI={10.1016/0165-1110(90)90037-C}, abstractNote={16 phenylenediamine-based disazo dyes were examined in the Salmonella/mammalian microsome assay with strains TA98, TA100 and TA1538. All of the dyes contain an alkoxy group ortho to one of the azo linkages. Increasing the size of this alkoxy substituent from 1 to 4 carbons led to a decrease in mutagenic activity in certain instances while no change was noted in other cases. Comparison of the mutagenicity of the disazo dyes with their potential reductive-cleavage products suggests that (1) the reductive-cleavage products are not solely responsible for the mutagenicity of the disazo dyes, and (2) significant reductive-cleavage of the disazo dyes is not taking place in the standard Salmonella assay.}, number={1}, journal={MUTATION RESEARCH}, author={ESANCY, JF and FREEMAN, HS and CLAXTON, LD}, year={1990}, month={Jan}, pages={23–38} }
 @article{sokolowskagajda_freeman_1990, title={THE SYNTHESIS OF DISPERSE AND CATIONIC DYES FROM ACID DYE STRUCTURES}, volume={14}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(90)87004-M}, abstractNote={This paper is concerned with the conversion of some mono- and di-sulfonated naphthol azo dyes to disperse dyes suitable for poly(ethyleneterephthalate) fibers, and cationic dyes for cationic dyeable polyester and acrylic fibers. The chemical structure of these new dyes has been confirmed by 1H-NMR, FAB or DCI mass spectrometry, and in some cases by elemental analysis. Some fastness properties and absorption spectral data of both types of dyes are also reported, as well as an interesting limitation in the naphthalene-based acid dyes suitable for the described conversion.}, number={1}, journal={DYES AND PIGMENTS}, author={SOKOLOWSKAGAJDA, J and FREEMAN, HS}, year={1990}, pages={35–48} }
 @inproceedings{freeman_esancy_esancy_claxton_1990, title={The design of non-mutagenic replacements for some mutagenic dyes and dye intermediates}, booktitle={Book of papers: 1990 international conference & exhibition, October 1-3, Sheraton Boston Hotel, Boston, Mass.}, publisher={Research Triangle Park, N.C.: American Association of Textile Chemists and Colorists}, author={Freeman, H.S. and Esancy, J.F. and Esancy, M.K. and Claxton, L.D.}, year={1990}, pages={180–188} }
 @article{freeman_sokolowskaogajda_hao_1989, title={13C NMR analysis of some azo and anthraquinone textile dyes}, volume={21}, number={4}, journal={Textile Chemist and Colorist}, author={Freeman, H. S. and SokolowskaOGajda, J. and Hao, Z.}, year={1989}, pages={24} }
 @article{voyksner_pack_haney_freeman_hsu_1989, title={DETERMINATION OF THE PHOTODEGRADATION PRODUCTS OF BASIC YELLOW-2 BY THERMOSPRAY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY}, volume={18}, ISSN={["0887-6134"]}, DOI={10.1002/bms.1200181208}, abstractNote={Like most dyes, Basic Yellow 2 (BY-2) fades upon prolonged exposure to light. Light-induced fading is a complex process that is also affected by heat and humidity. In order to better understand the photodegradation process and to identify the various photodegradation products of BY-2, fabric samples and solutions containing BY-2 were exposed to a variety of fading conditions. The analysis of faded BY-2 dyed fabric extracts by high-performance liquid chromatography/mass spectrometry (HPLC/MS) indicated the reduction and hydrolysis of the CNH2+ group to form primarily benzophenone derivatives, as well as various demethylated products. Due to the absence of fragmentation in the thermospray spectra (only [M + H]+ ions were observed) the dye extracts were analyzed by gas chromatography/mass spectrometry (GC/MS) to confirm the identity of the degradation products. Many of the degradation products were sufficiently volatile for analysis by GC/MS. Mass spectra of the photodegradation products of BY-2 exhibited molecular ions and structurally important fragment ions to complement the thermospray data. The mass spectral data indicated that the most prevalent degradation product formed was ((CH3)2NC6H4)2C0 (Michler's ketone). Hydrolysis of the CNH2+ group to C0 is the main color-destroying reaction in the fading of BY-2. Demethylation products which can alter the shades of color were also detected in the faded BY-2 samples.}, number={12}, journal={BIOMEDICAL AND ENVIRONMENTAL MASS SPECTROMETRY}, author={VOYKSNER, RD and PACK, TW and HANEY, CA and FREEMAN, HS and HSU, WN}, year={1989}, month={Dec}, pages={1079–1086} }
 @inproceedings{freeman_haney_mcintosh_voyksner_1989, title={Determination of the photodegradation products of Disperse Orange 29 by GC/MS and HPLC/MS}, booktitle={37th ASMS Conference on Mass Spectrometry and Allied Topics: May 21-26, 1989, Miami Beach, Florida}, publisher={Denver, Colo. : ASMS}, author={Freeman, H.S. and Haney, C.A. and McIntosh, S.A. and Voyksner, R.D.}, year={1989}, pages={1453} }
 @article{freeman_mcintosh_1989, title={PHOTOLYTIC PROPERTIES OF ORTHO-SUBSTITUTED 4-[N,N-BIS(BETA-HYDROXYETHYL)AMINO]AZOBENZENES IN POLYMER SUBSTRATES}, volume={59}, ISSN={["1746-7748"]}, DOI={10.1177/004051758905900606}, abstractNote={The synthesis of some novel derivatives of 4-[ N,N-bis(β-hydroxyethyl)- amino]azobenzene is reported, and the effects of ortho-substituents on photoinduced trans → cis isomerism about the azo group, mass spectral behavior, and the photost ability of these dyes are described. An ortho-nitro group inhibits trans → cis photo- isomerism about the azo group and affords poor photostability. Those ortho-substituted dyes showing a greater tendency to undergo photoinduced trans → cis isomerism and recover quickly are also more photostable and less subject to rupture at the β-nitrogen- carbon bond in the mass spectrometer. The photolysis experiments were done using acetate and triacetate film and fiber, and the mass spectrometric analyses were done by direct probe using the electron-impact technique.}, number={6}, journal={TEXTILE RESEARCH JOURNAL}, author={FREEMAN, HS and MCINTOSH, SA}, year={1989}, month={Jun}, pages={343–349} }
 @article{freeman_hao_1989, title={PROTON MAGNETIC-RESONANCE SPECTRA OF SOME NAPHTHALENE DERIVATIVES IN DMSO-D6}, volume={10}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(89)85013-2}, abstractNote={The chemical shifts of the ring protons of 14 naphthalenesulfonic acid derivatives have been assigned from 250 MHz spectra. In addition, the spectra of a large number of monosubstituted naphthalenes were recorded using DMSO-d 6 as solvent. It is clear from this latter part of the study that DMSO-d 6 often causes an upfield (to a lower δ value) shift (relative to those in CDCl 3 ) in the δ values of the protons in this ring system. It is also clear that a number of signals are less resolved when DMSO-d 6 is used in lieu of CDCl 3 , at the field strength of 250MHz.}, number={4}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and HAO, ZM}, year={1989}, pages={247–257} }
 @article{freeman_hao_hsu_1989, title={THE CHROMATOGRAPHIC BEHAVIOR OF SOME HYDROPHILIC DYES AND DYE INTERMEDIATES ON THIN-LAYERS OF STRONG AND WEAK ION-EXCHANGERS}, volume={12}, ISSN={["0148-3919"]}, DOI={10.1080/01483918908051770}, abstractNote={Abstract The chromatographic behavior of some polar organic dyes and dye intermediates on thin layers of various forms of cationic and anionic exchange resins has been investigated. The results of this study indicate that the stationary ion and the mobile ion of both types of exchangers greatly affect both the level of tailing and the Rf values of the adsorbed compounds. It is also clear from this study that these resins are more suitable for evaluating the relatively simple dyes containing an SO3Na group than the higher molecular weight polyazo direct dyes used on cellulosic substrates, and that the Li+ and H+ forms of the cation exchangers work better than their counterparts. On the other hand, cationic dye molecules require the use of anion exchangers, with the −OAc form giving better chromatograms than the C104− form.}, number={6}, journal={JOURNAL OF LIQUID CHROMATOGRAPHY}, author={FREEMAN, HS and HAO, Z and HSU, WN}, year={1989}, pages={919–935} }
 @article{freeman_hao_kim_1989, title={The design and synthesis of cellulose-substantive dyes}, volume={78}, number={4}, journal={American Dyestuff Reporter}, author={Freeman, H. S. and Hao, Z. and Kim, S. D.}, year={1989}, pages={15} }
 @article{mcintosh_freeman_singh_1989, title={X-RAY CRYSTAL-STRUCTURE OF THE DYES 2-NITRO-4'-[N,N-BIS(BETA-HYDROXYETHYL)AMINO]AZOBENZENE AND 2-CYANO-4'-[N,N-BIS-(BETA-HYDROXYETHYL)AMINO]AZOBENZENE}, volume={59}, ISSN={["1746-7748"]}, DOI={10.1177/004051758905900703}, abstractNote={ X-ray diffractometer data have been used to determine the crystal structure of the 2-nitro and 2-cyano derivatives of 4'-[ N,N-bis(β-hydroxyethyl)amino]azobenzene. The structures were solved by direct methods and refined by least squares to R = 0.0352 (CN) and 0.0486 (NO2) for 1294 and 2661 independent reflections, re spectively. The nitro derivative is nonplanar with a dihedral angle of 42.1° between the two phenyl rings. The effect of the nitro group on the geometry of the molecule is discussed. On the other hand, the cyano derivative possesses a planar azobenzene skeleton. The dihedral angle between the two phenyl rings is 5.5° in this case. The O(4)-atom of the nitro substituent lies very close to the N(1)-atom of the azo moiety, as had been suggested previously to account for the low lightfastness of some closely related ortho-nitro azo dyes. The C(1)—N(1),N(1)—N(2), and N(2)—C(7) bond lengths of the azobenzene skeleton are surprisingly similar for the two dyes. }, number={7}, journal={TEXTILE RESEARCH JOURNAL}, author={MCINTOSH, SA and FREEMAN, HS and SINGH, P}, year={1989}, month={Jul}, pages={389–395} }
 @article{freeman_moser_whaley_1988, title={NEW PHOSPHONIC ACID REACTIVE DYES FOR COTTON}, volume={9}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(88)85004-6}, abstractNote={The synthesis of some new azo reactive dyes which contain a phosphonic acid group in a pendant chain of the coupling component is described. Four phosphonic acid couplers have been prepared and coupled to two different diazo compounds to produce eight reactive dyes which have good washfastness properties once fixed on cotton. The structures of the dyes were confirmed with the aid of 1H-NMR.}, number={1}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and MOSER, LS and WHALEY, WM}, year={1988}, pages={57–65} }
 @article{freeman_hsu_esancy_esancy_1988, title={PROTON MAGNETIC-RESONANCE SPECTRA OF SOME NAPHTHALENE DERIVATIVES}, volume={9}, ISSN={["1873-3743"]}, DOI={10.1016/0143-7208(88)85005-8}, abstractNote={The chemical shifts of the ring protons of some monosubstituted naphthalenes were assigned from 250 MHz spectra, and the assignments were used to assist in the interpretation of the spectra of a number of naphthalene sulfonic acids which are commonly used as dyestuff intermediates. A table of parameters is presented which would assist in the identification of complex azo dyes that are derived from these naphthalene derivatives.}, number={1}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and HSU, WN and ESANCY, JF and ESANCY, MK}, year={1988}, pages={67–82} }
 @article{freeman_hao_mcintosh_mills_1988, title={PURIFICATION OF SOME WATER-SOLUBLE AZO DYES BY HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY}, volume={11}, ISSN={["0148-3919"]}, DOI={10.1080/01483919808068327}, abstractNote={Abstract High-speed countercurrent chromatography (CCC) has been used to prepare preparative amounts of pure magenta azo dyes by a method involving the continuous extraction of an aqueous solution of the dyes by a suitable mobile phase. This slight variation in the normal way of running CCC separations permits both the removal of the impurities from the desired color component and an increase in the quantity of dye that can be purified in a single experiment.}, number={1}, journal={JOURNAL OF LIQUID CHROMATOGRAPHY}, author={FREEMAN, HS and HAO, Z and MCINTOSH, SA and MILLS, KP}, year={1988}, pages={251–266} }
 @article{freeman_esancy_esancy_mills_whaley_dabney_1987, title={AN APPROACH TO THE DESIGN OF NONMUTAGENIC AZO DYES .1. THE IDENTIFICATION OF NONMUTAGENIC PRECURSORS AND POTENTIAL METABOLITES}, volume={8}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(87)85034-9}, abstractNote={This paper describes a strategy for the development of non-mutagenic dyes by identifying and elaborating some non-genotoxic precursors. The approach presented makes use of the numerous published articles which describe the results of the mutagenicity and carcinogenicity testing of azo dyes and their intermediates. A number of chemical intermediates have been evaluated in this study as potential replacements for known carcinogenic dye intermediates which have been used in the past to produce dyes possessing good physical and chemical properties. Several of the intermediates examined were found to be non-mutagenic, and were converted to azo dyes which were themselves non-mutagenic. The results of this study suggest that the development of non-carcinogenic azo dyes could be accomplished by employing an approach which would utilize non-mutagenic intermediates and also take into consideration the potential genotoxicity of the metabolites resulting from reductive cleavage of the azo linkages.}, number={6}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and ESANCY, JF and ESANCY, MK and MILLS, KP and WHALEY, WM and DABNEY, BJ}, year={1987}, pages={417–430} }
 @article{calogero_freeman_esancy_whaley_dabney_1987, title={AN APPROACH TO THE DESIGN OF NONMUTAGENIC AZO DYES .2. POTENTIAL REPLACEMENTS FOR THE BENZIDINE MOIETY OF SOME MUTAGENIC AZO DYESTUFFS}, volume={8}, ISSN={["1873-3743"]}, DOI={10.1016/0143-7208(87)85035-0}, abstractNote={This paper describes the synthesis of 5,5'-diamino-2,2'-bipyridine and its subsequent evaluation as a possible replacement for the benzidine residue in some well-known carcinogenic henzidine-based azo dyes. The results of this investigation suggest that this diaminobipyridine is much less genotoxic than benzidine itself, and that certain dyes derived from it are also less genotoxic than their benzidine counterparts. The compounds prepared in this study were evaluated in the standard Ames mutagenicity test, and in an interesting modification developed by Prival and coworkers. Each compound was found to be more active in the latter protocol. The synthesis of the diamine and of four azo dyes derived from it is described.}, number={6}, journal={DYES AND PIGMENTS}, author={CALOGERO, F and FREEMAN, HS and ESANCY, JF and WHALEY, WM and DABNEY, BJ}, year={1987}, pages={431–447} }
 @inproceedings{freeman_voyksner_pack_hsu_haney_1987, title={Determination of the photodegradation products of Basic Yellow 2 by thermospray HPLC/MS and GC/MS}, booktitle={ASMS Conference on Mass Spectrometry and Allied Topics}, publisher={Denver, Colo. : ASMS}, author={Freeman, H.S. and Voyksner, R.D. and Pack, T.W. and Hsu, W.N. and Haney, C.A.}, year={1987}, pages={155–156} }
 @article{freeman_hsu_1987, title={PHOTOLYTIC BEHAVIOR OF SOME POPULAR DISPERSE DYES ON POLYESTER AND NYLON SUBSTRATES}, volume={57}, ISSN={["1746-7748"]}, DOI={10.1177/004051758705700407}, abstractNote={The photodegradation products that form when disperse red 1, red 17, and blue 3 dyed fabrics and films are exposed to carbon arc and xenon arc light sources have been identified. The effects of black panel and dye carrier on the nature of the deg radation products and the fading process itself were also studied. The results of this research indicate that the same photodegradation products occur in comparisons in volving carbon arc versus xenon arc exposures, polyester versus nylon substrates, black panel versus no black panel exposures, and exposures of carrier dyed versus no carrier dyed PET. It is clear that photo-reduction pathways account for the products that form when the two azo disperse dyes (red 1 and red 17) photofade, but photo oxidation characterizes the fading of the anthraquinone disperse dye blue 3. The pho todegradation products were determined with the aid of GC mass spectrometry and by TLC comparisons with authentic samples.}, number={4}, journal={TEXTILE RESEARCH JOURNAL}, author={FREEMAN, HS and HSU, WN}, year={1987}, month={Apr}, pages={223–234} }
 @article{mills_freeman_whaley_carroll_1987, title={PURIFICATION PROCEDURES FOR SYNTHETIC DYES .3. HPLC SEPARATION OF THE COMPONENTS OF 1,4-BIS(2,6-DIISOPROPYLANILINO)ANTHRAQUINONE}, volume={8}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(87)85029-5}, abstractNote={Abstract Reverse-phase thin-layer chromatography (TLC) of a laboratory-synthesized sample of 1,4-bis(2,6-diisopropylanilino)anthraquinone revealed that the dye contained three components (violet, blue and blue-green). Analytically HPLC then showed that the blue-green component was a mixture of blue-green and green dyes. The four dyes were separated by HPLC, and each was identified by 1 H-NMR and mass-spectral analysis. The latter three dyes were shown to be isomeric compounds which result from the presence of a small amount of 2,4-diisopropylaniline in commercial 2,6-diisopropylaniline.}, number={5}, journal={DYES AND PIGMENTS}, author={MILLS, KP and FREEMAN, HS and WHALEY, WM and CARROLL, FI}, year={1987}, pages={389–395} }
 @article{freeman_williard_hsu_1986, title={PURIFICATION PROCEDURES FOR SYNTHETIC DYES .1. DRY COLUMN CHROMATOGRAPHY}, volume={7}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(86)80008-0}, abstractNote={The suitability of dry column chromatography for the purification of synthetic dyestuffs has been investigated. The results of this study indicate that the utility of this method for the generation of gram quantities of pure dyestuffs is limited, from a practical standpoint, to disperse dyes. Although dry column chromatography appears to be impractical for the purification of gram quantities of acid and direct dyes, relatively simple monoazo acid dyes were successfully purified in smaller quantities by this procedure. The simplicity and low cost of this method make it an excellent way to obtain useful amounts of disperse dyes which are pure enough for use in biological assays such as Ames tests.}, number={6}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and WILLIARD, CS and HSU, WN}, year={1986}, pages={397–405} }
 @article{freeman_williard_1986, title={PURIFICATION PROCEDURES FOR SYNTHETIC DYES .2. COUNTERCURRENT CHROMATOGRAPHY}, volume={7}, ISSN={["0143-7208"]}, DOI={10.1016/0143-7208(86)80009-2}, abstractNote={The suitability of countercurrent chromatography as a method for purifying preparative amounts of disperse dyes and direct dyes has been investigated. Solvent pairs were developed which afforded partition coefficients needed to effect the purification of dyes of these types. Although this procedure was found to give good separation of complex dye mixtures, the low solubility of the dyes in the solvent pairs prevents it from being an effective method of preparing gram quantities of analytically pure dyes.}, number={6}, journal={DYES AND PIGMENTS}, author={FREEMAN, HS and WILLIARD, CS}, year={1986}, pages={407–417} }
 @article{freeman_freedman_muftah_1982, title={A regiospecific inter-action of meta-substituted diarylamines and phosphorus trichloride}, volume={47}, DOI={10.1021/jo00145a006}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA regiospecific interaction of meta-substituted diarylamines and phosphorus trichlorideHarold S. Freeman, Leon D. Freedman, and Muna A. MuftahCite this: J. Org. Chem. 1982, 47, 24, 4637–4640Publication Date (Print):November 1, 1982Publication History Published online1 May 2002Published inissue 1 November 1982https://pubs.acs.org/doi/10.1021/jo00145a006https://doi.org/10.1021/jo00145a006research-articleACS PublicationsRequest reuse permissionsArticle Views113Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts}, journal={Journal of Organic Chemistry}, author={Freeman, H. S. and Freedman, L. D. and Muftah, M. A.}, year={1982}, pages={4637} }
 @article{mcdermed_freeman_1982, title={Stereochemistry of dopamine receptor agonists}, volume={37}, DOI={10.1016/b978-0-08-027391-4.50022-8}, abstractNote={In order to help understand the mode of binding of dopamine agonists to their receptors, four agonists of the 2-aminotetralin series were resolved into (+)- and (−)-enantiomers, their absolute configurations were determined, and their receptor affinities were evaluated in binding assays. The most important result seen was an inversion of stereochemical requirement which is governed by the location of hydroxyl groups in the aromatic ring. Thus, 5- and 5,6-dihydroxyl compounds require the 2S configuration while 7- and 6,7-dihydroxyl compounds must be 2R. This implies a specific orientation of such ligands to the receptor, for which a model is proposed.}, journal={Advances in Biochemical Engineering/biotechnology}, author={McDermed, J. D. and Freeman, H. S.}, year={1982}, pages={179} }
 @article{freeman_freedman_1981, title={Dihydrophenophosphazines via the interactions of diarylamines and phosphorus trichloride: Applications and limitations}, volume={171}, DOI={10.1021/bk-1981-0171.ch061}, abstractNote={In 1971 it was shown (1) that the interaction of diphenylamine and phosphorus trichloride at 210° (followed by treatment of the reaction mixture with water) yields not only the previously described phosphine oxide 1 but also the spirophosphonium chloride 2. The mechanism of formation of the latter compound (a derivative of PV) from phosphorus trichloride has not been elucidated, but the following mechanism suggested (2) for the formation of 1 seems reasonable: Studies (2,3) have also been reported of the reaction of phosphorus trichloride with diarylamines containing p-methyl or p-chloro substituents. In every case, the expected ring- substituted derivatives of 1 and 2 were obtained after the reaction mixture was treated with water. The interaction of N-phenyl-O-toluidine and phosphorus trichloride at 200°C also gave a reaction mixture from which the expected phosphine oxide was isolated (3). None of the corresponding spirophosphonium chloride, however, could be obtained. The failure to isolate}, journal={ACS Symposium Series}, author={Freeman, H. S. and Freedman, L. D.}, year={1981}, pages={291} }
 @article{freeman_freedman_1981, title={SYNTHESIS OF TERTIARY PHOSPHINE DERIVATIVES OF DIHYDROPHENOPHOSPHAZINE}, volume={46}, ISSN={["1520-6904"]}, DOI={10.1021/jo00339a024}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of tertiary phosphine derivatives of dihydrophenophosphazineHarold S. Freeman and Leon D. FreedmanCite this: J. Org. Chem. 1981, 46, 26, 5373–5376Publication Date (Print):December 1, 1981Publication History Published online1 May 2002Published inissue 1 December 1981https://pubs.acs.org/doi/10.1021/jo00339a024https://doi.org/10.1021/jo00339a024research-articleACS PublicationsRequest reuse permissionsArticle Views455Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts}, number={26}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={FREEMAN, HS and FREEDMAN, LD}, year={1981}, pages={5373–5376} }
 @inbook{mcdermed_freeman_ferris_1979, title={Enantioselectivity in the binding of (+) - and (-) - 2 - amino - 6,7 dihydroxy - 1,2,3,4 - tetrahydronaphthalene and related agonists to dopamine receptors}, ISBN={9780080226507}, DOI={10.1016/b978-1-4832-8363-0.50174-9}, abstractNote={The potent DA agonist 5 was resolved into enantiomers. The absolute configurations of the enantiomers of 3 and 5 were determined by chemical degradation. These compounds were tested as inhibitors of 3H-DA binding to membrane fragments from rat striatum. It was found that the configuration of the more potent enantiomer of 5 is opposite to that of 3 and APO. This is relevant to the mode of binding of such agonists to DA receptors.}, booktitle={Catecholamines: basic and clinical frontiers: proceedings of the Fourth International Catecholamine Symposium, Pacific Grove, California, September 17-22, 1978}, publisher={New York: Pergamon Press}, author={McDermed, J.D. and Freeman, H.S. and Ferris, R.M.}, editor={E. Usdin, I. J. Kopin and Barchas, J.Editors}, year={1979} }
 @article{freeman_butler_freedman_1978, title={ACETYLDIARYLAMINES BY ARYLATION OF ACETANILIDES - SOME APPLICATIONS AND LIMITATIONS}, volume={43}, ISSN={["1520-6904"]}, DOI={10.1021/jo00420a018}, abstractNote={ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAcetyldiarylamines by arylation of acetanilides. Some applications and limitationsHarold S. Freeman, Jack R. Butler, and Leon D. FreedmanCite this: J. Org. Chem. 1978, 43, 26, 4975–4978Publication Date (Print):December 1, 1978Publication History Published online1 May 2002Published inissue 1 December 1978https://pubs.acs.org/doi/10.1021/jo00420a018https://doi.org/10.1021/jo00420a018research-articleACS PublicationsRequest reuse permissionsArticle Views653Altmetric-Citations50LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts}, number={26}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={FREEMAN, HS and BUTLER, JR and FREEDMAN, LD}, year={1978}, pages={4975–4978} }
 @article{andrews_davis_freeman_mcdermed_poat_woodruff_1978, title={Effects of the (+) and (-) enantiomers of 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene on dopamine receptors and on dopamine uptake}, volume={64}, number={3}, journal={British Journal of Pharmacology}, author={Andrews, G.D. and Davis, A. and Freeman, H.S. and McDermed, J.D. and Poat, J.A. and Woodruff, G.N.}, year={1978}, pages={433} }
 @article{mcdermed_mckenzie_freeman_1976, title={SYNTHESIS AND DOPAMINERGIC ACTIVITY OF (+/-)-1,2,3,4-TETRAHYDRONAPHTHALENE, (+)-1,2,3,4-TETRAHYDRONAPHTHALENE, AND (-)-2-DIPROPYLAMINO-5-HYDROXY-1,2,3,4-TETRAHYDRONAPHTHALENE}, volume={19}, ISSN={["0022-2623"]}, DOI={10.1021/jm00226a021}, abstractNote={In an effort to identify further the structural requirements for central dopamine receptor agonists, some monohydroxyl analogs of the known agonist 5,6-dihydroxy-2-dipropylamino-1,2,3,4-tetrahydronaphthalene were synthesized. They were examined for production of emesis in dogs and stereotyped behavior in rats. The most potent was 5-hydroxy-2-dipropylamino-1,2,3,4-tetrahydronaphthalene, which was more potent than apomorphine but less so than the dihydroxyl analog. The two enantiomers of the monohydroxyl analog were synthesized by conventional methods from an optically active intermediate, 2-benzylamino-5-methoxy-1,2,3,4-tetrahydronaphthalene. The resolution of this amine was performed with the aid of mandelic acid. Dopaminergic activity was found to be confined to the levo enantiomer. Requirements for both substitution and chirality in the tetralines were found to correspond closely to those known for the dopaminergic aporphines.}, number={4}, journal={JOURNAL OF MEDICINAL CHEMISTRY}, author={MCDERMED, JD and MCKENZIE, GM and FREEMAN, HS}, year={1976}, pages={547–549} }