@article{kirmaier_song_yang_schwartz_hindin_diers_loewe_tomizaki_chevalier_ramos_et al._2010, title={Excited-State Photodynamics of Perylene-Porphyrin Dyads 5 Tuning Light-Harvesting Characteristics via Perylene Substituents, Connection Motif, and Three-Dimensional Architecture}, volume={114}, ISSN={["1520-5207"]}, DOI={10.1021/jp910705q}, abstractNote={Seven perylene-porphyrin dyads were examined with the goal of identifying those most suitable for components of light-harvesting systems. The ideal dyad should exhibit strong absorption by the perylene in the green, undergo rapid and efficient excited-state energy transfer from perylene to porphyrin, and avoid electron-transfer quenching of the porphyrin excited state by the perylene in the medium of interest. Four dyads have different perylenes at the p-position of the meso-aryl group on the zinc porphyrin. The most suitable perylene identified in that set was then incorporated at the m- or o-position of the zinc porphyrin, affording two other dyads. An analogue of the o-substituted architecture was prepared in which the zinc porphyrin was replaced with the free base porphyrin. The perylene in each dyad is a monoimide derivative; the perylenes differ in attachment of the linker (either via a diphenylethyne linker at the N-imide or an ethynylphenyl linker at the C9 position) and the number (0-3) of 4-tert-butylphenoxy groups (which increase solubility and slightly alter the electrochemical potentials). In the p-linked dyad, the monophenoxy perylene with an N-imide diphenylethyne linker is superior in providing rapid and essentially quantitative energy transfer from excited perylene to zinc porphyrin with minimal electron-transfer quenching in both toluene and benzonitrile. The dyads with the same perylene at the m- or o-position exhibited similar results except for one case, the o-linked dyad bearing the zinc porphyrin in benzonitrile, where significant excited-state quenching is observed; this phenomenon is facilitated by close spatial approach of the perylene and porphyrin and the associated thermodynamic/kinetic enhancement of the electron-transfer process. Such quenching does not occur with the free base porphyrin because electron transfer is thermodynamically unfavorable even in the polar medium. The p-linked dyad containing a zinc porphyrin attached to a bis(4-tert-butylphenoxy)perylene via an ethynylphenyl linker at the C9 position exhibits ultrafast and quantitative energy transfer in toluene; the same dyad in benzonitrile exhibits ultrafast (<0.5 ps) perylene-to-porphyrin energy transfer, rapid (∼5 ps) porphyrin-to-perylene electron transfer, and fast (∼25 ps) charge recombination to the ground state. Collectively, this study has identified suitable perylene-porphyrin constructs for use in light-harvesting applications.}, number={45}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Kirmaier, Christine and Song, Hee-eun and Yang, Eunkyung and Schwartz, Jennifer K. and Hindin, Eve and Diers, James R. and Loewe, Robert S. and Tomizaki, Kin-ya and Chevalier, Fabien and Ramos, Lavoisier and et al.}, year={2010}, month={Nov}, pages={14249–14264} }
 @misc{lindsey_loewe_muthukumaran_ambroise_2009, title={Synthesis of phosphono-substituted porphyrin compounds for attachment to metal oxide surfaces}, volume={7,553,977}, number={2009 Jun 30}, author={Lindsey, J. S. and Loewe, R. S. and Muthukumaran, K. and Ambroise, A.}, year={2009} }
 @misc{lindsey_loewe_muthukumaran_ambroise_2008, title={Synthesis of phosphono-substituted porphyrin compounds for attachment to metal oxide surfaces}, volume={7,314,941}, number={2008 Jan. 1}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Lindsey, J. S. and Loewe, R. S. and Muthukumaran, K. and Ambroise, A.}, year={2008} }
 @misc{bocian_lindsey_liu_yasseri_loewe_2007, title={Attachment of organic molecules to group III, IV or V substrates}, volume={7,230,268}, number={2007 Jun. 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bocian, D. F. and Lindsey, J. S. and Liu, Z.-M. and Yasseri, A. A. and Loewe, R. S.}, year={2007} }
 @misc{bocian_lindsey_liu_yesseri_misra_zhao_li_surthi_loewe_2007, title={High temperature attachment of organic molecules to substrates}, volume={7,223,628}, number={2007 May 29}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bocian, D. F. and Lindsey, J. and Liu, Z. and Yesseri, A. A. and Misra, V. and Zhao, Q. and Li, Q. and Surthi, S. and Loewe, R. S.}, year={2007} }
 @article{zaidi_loewe_clark_jacob_lindsey_2006, title={Nearly chromatography-free synthesis of the A(3)B-porphyrin 5-(4-hydroxymethylphenyl)-10,15,20-tri-p-tolylporphinatozinc(II)}, volume={10}, ISSN={["1520-586X"]}, DOI={10.1021/op0502553}, abstractNote={Rational routes to synthetic porphyrins bearing distinct meso-substituents have typically been implemented at modest scale ( 10:1 ratio (versus 4:1 using EtMgBr), (iii) isolation of the dibutyltin complex of the 1,9-diacyl...}, number={2}, journal={ORGANIC PROCESS RESEARCH & DEVELOPMENT}, author={Zaidi, SHH and Loewe, RS and Clark, BA and Jacob, MJ and Lindsey, JS}, year={2006}, pages={304–314} }
 @misc{lindsey_loewe_muthukumaran_ambroise_2006, title={Synthesis of phosphono-substituted porphyrin compounds for attachment to metal oxide surfaces}, volume={7,148,361}, number={2006 Dec. 12}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Lindsey, J. and Loewe, R. S. and Muthukumaran, K. and Ambroise, A.}, year={2006} }
 @misc{bocian_lindsey_liu_yasseri_loewe_2005, title={Attachment of organic molecules to group III, IV or V substrates}, volume={6,943,054}, number={2005 Sep. 13}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bocian, D. F. and Lindsey, J. S. and Liu, Z. and Yasseri, A. A. and Loewe, R. S.}, year={2005} }
 @article{wei_syomin_loewe_lindsey_zaera_bocian_2005, title={Structural and electron-transfer characteristics of carbon-tethered porphyrin monolayers on Si(100)}, volume={109}, ISSN={["1520-6106"]}, DOI={10.1021/jp044558v}, abstractNote={Structural and electron-transfer characteristics are reported for two classes of zinc porphyrin monolayers attached to Si(100) surfaces via Si-C bonds. One class, designated ZnP(CH(2))(n)- (n = 2-4), contains an alkyl linker appended to the meso-position of the porphyrin, with the nonlinking substituents being p-tolyl groups. The other, designated ZnPPh(CH(2))(n)- (n = 0-3), contains a phenyl or phenylalkyl linker appended to the meso-position of the porphyrin, with the nonlinking substituents being mesityl groups. Both classes of zinc porphyrin monolayers on Si(100) were examined using Fourier transform infrared spectroscopy and various electrochemical methods. The studies reveal the following: (1) The structural and electron-transfer characteristics of the ZnP(CH(2))(n)- and ZnPPh(CH(2))(n)- monolayers are generally similar to those of monolayers formed from porphyrins with analogous linkers, but anchored with an O, a S, or a Se atom. (2) The ZnP(CH(2))(n)-, ZnPPh-, and ZnPPhCH(2)- monolayers exhibit lower saturation coverages and have their porphyrin ring more tilted with respect to the surface normal than the ZnPPh(CH(2))(2)- and ZnPPh(CH(2))(3)- monolayers. (3) The electron-transfer rates for both the ZnP(CH(2))(n)- and ZnPPh(CH(2))(n)- classes of monolayers monotonically decrease as the length of the linker increases. (4) For all the ZnP(CH(2))(n)- and ZnPPh(CH(2))(n)- monolayers, both electron-transfer rates and charge-dissipation rates decrease monotonically as the surface coverage increases. Collectively, the studies reported herein provide a detailed picture of how the linker type influences the structural and electron-transfer characteristics of these general classes of monolayers.}, number={13}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Wei, LY and Syomin, D and Loewe, RS and Lindsey, JS and Zaera, F and Bocian, DF}, year={2005}, month={Apr}, pages={6323–6330} }
 @misc{loewe_tomizaki_lindsey_2005, title={Synthesis of perylene-porphyrin building blocks and polymers thereof for the production of light-harvesting arrays}, volume={6,916,982}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Loewe, R. S. and Tomizaki, K.-Y. and Lindsey, J. S.}, year={2005} }
 @article{yasseri_syomin_malinovskii_loewe_lindsey_zaera_bocian_2004, title={Characterization of self-assembled monolayers of porphyrins bearing multiple thiol-derivatized rigid-rod tethers}, volume={126}, ISSN={["0002-7863"]}, DOI={10.1021/ja047723t}, abstractNote={A series of multithiol-functionalized zinc porphyrins has been prepared and characterized as self-assembled monolayers (SAMs) on Au. The molecules, designated ZnPS(n) (n = 1-4), contain from one to four [(S-acetylthio)methyl]phenylethynylphenyl groups appended to the meso-position of the porphyrin; the other meso-substituents are phenyl groups. For the dithiol-functionalized molecules, both the cis- and the trans-appended structures were examined. The ZnPS(n) SAMs were investigated using X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and various electrochemical methods. The studies reveal the following characteristics of the ZnPS(n) SAMs. (1) The ZnPS(n) molecules bind to the Au surface via a single thiol regardless of the number of thiol appendages that are available per molecular unit. (2) The porphyrins in the ZnPS(3) and ZnPS(4) SAMs bind to the surface in a more upright orientation than the porphyrins in the ZnPS(1), cis-ZnPS(2), and trans-ZnPS(2) SAMs. The porphyrins in the ZnPS(3) and ZnPS(4) SAMs are also more densely packed than those in the cis-ZnPS(2) and trans-ZnPS(2) SAMs. The packing density of the ZnPS(3) and ZnPS(4) SAMs is similar to that of the ZnPS(1) SAMs, despite the larger size of the molecules in the former SAMs. (3) The thermodynamics and kinetics of electron transfer are generally similar for all of the ZnPS(n) SAMs. The general similarities in the electron-transfer characteristics for all of the SAMs are attributed to the similar binding motif.}, number={38}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Yasseri, AA and Syomin, D and Malinovskii, VL and Loewe, RS and Lindsey, JS and Zaera, F and Bocian, DF}, year={2004}, month={Sep}, pages={11944–11953} }
 @article{balakumar_lysenko_carcel_malinovskii_gryko_schweikart_loewe_yasseri_liu_bocian_et al._2004, title={Diverse redox-active molecules bearing O-, S-, or Se-terminated tethers for attachment to silicon in studies of molecular information storage}, volume={69}, ISSN={["1520-6904"]}, DOI={10.1021/jo034944t}, abstractNote={A molecular approach to information storage employs redox-active molecules tethered to an electroactive surface. Attachment of the molecules to electroactive surfaces requires control over the nature of the tether (linker and surface attachment group). We have synthesized a collection of redox-active molecules bearing different linkers and surface anchor groups in free or protected form (hydroxy, mercapto, S-acetylthio, and Se-acetylseleno) for attachment to surfaces such as silicon, germanium, and gold. The molecules exhibit a number of cationic oxidation states, including one (ferrocene), two [zinc(II)porphyrin], three [cobalt(II)porphyrin], or four (lanthanide triple-decker sandwich compound). Electrochemical studies of monolayers of a variety of the redox-active molecules attached to Si(100) electrodes indicate that molecules exhibit a regular mode of attachment (via a Si-X bond, X = O, S, or Se), relatively homogeneous surface organization, and robust reversible electrochemical behavior. The acetyl protecting group undergoes cleavage during the surface deposition process, enabling attachment to silicon via thio or seleno groups without handling free thiols or selenols.}, number={5}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Balakumar, A and Lysenko, AB and Carcel, C and Malinovskii, VL and Gryko, DT and Schweikart, KH and Loewe, RS and Yasseri, AA and Liu, ZM and Bocian, DF and et al.}, year={2004}, month={Mar}, pages={1435–1443} }
 @article{hindin_forties_loewe_ambroise_kirmaier_bocian_lindsey_holten_knox_2004, title={Excited-state energy flow in covalently linked multiporphyrin arrays: The essential contribution of energy transfer between nonadjacent chromophores}, volume={108}, ISSN={["1520-6106"]}, DOI={10.1021/jp047803j}, abstractNote={A series of multiporphyrin arrays has been studied to probe the contribution of energy transfer between second-neighbor ("nonadjacent") porphyrins and to determine the rate of energy transfer between identical porphyrins at adjacent sites. The arrays, organized in linear or branched architectures, contain up to 21 constituents, domains of 2-5 zinc porphyrins, and a single energy trap. The study has involved iterative cycles of molecular design, synthesis, determination of rates via transient absorption spectroscopy, and kinetic analysis. A rate constant of (30 ′ 10 ps) - 1 is deduced for bidirectional energy transfer between adjacent zinc porphyrins joined by a diphenylethyne linker. The value is (50 ′ 10 ps) - 1 when the porphyrin-linker internal rotation is hindered by o,o'-methyl groups on one aryl ring of the linker. Rates of nonadjacent energy transfers are typically only 5-10-fold less than the rates of adjacent transfers. Thus, the nonadjacent pathway has a significant impact on the overall rate of energy flow to the trap, even in architectures as small as triads. These findings provide information that will be essential for the rational design of multichromophore arrays whose function is to transfer excitation energy efficiently over large distances to a trap site.}, number={34}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Hindin, E and Forties, RA and Loewe, RS and Ambroise, A and Kirmaier, C and Bocian, DF and Lindsey, JS and Holten, D and Knox, RS}, year={2004}, month={Aug}, pages={12821–12832} }
 @article{carcel_laha_loewe_thamyongkit_schweikart_misra_bocian_lindsey_2004, title={Porphyrin architectures tailored for studies of molecular information storage}, volume={69}, ISSN={["0022-3263"]}, DOI={10.1021/jo0498260}, abstractNote={A molecular approach to information storage employs redox-active molecules tethered to an electroactive surface. Zinc porphyrins tethered to Au(111) or Si(100) provide a benchmark for studies of information storage. Three sets of porphyrins have been synthesized for studies of the interplay of molecular design and charge-storage properties: (1) A set of porphyrins is described for probing the effect of surface attachment atom on electron-transfer kinetics. Each porphyrin bears a meso-CH2X group for surface attachment where X = OH, SAc, or SeAc. (2) A set of porphyrins is described for studying the effect of surface-charge density in monolayers. Each porphyrin bears a benzyl alcohol for surface attachment and three nonlinking meso substituents of a controlled degree of bulkiness. (3) A set of porphyrins is described that enables investigation of on-chip patterning of the electrolyte. Each porphyrin bears a formyl group distal to the surface attachment group for subsequent derivatization with a molecular entity that comprises the electrolyte. Taken together, this collection of molecules enables a variety of studies to elucidate design issues in molecular-based information storage.}, number={20}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Carcel, CM and Laha, JK and Loewe, RS and Thamyongkit, P and Schweikart, KH and Misra, V and Bocian, DF and Lindsey, JS}, year={2004}, month={Oct}, pages={6739–6750} }
 @article{muthukumaran_loewe_ambroise_tamaru_li_mathur_bocian_misra_lindsey_2004, title={Porphyrins bearing arylphosphonic acid tethers for attachment to oxide surfaces}, volume={69}, ISSN={["0022-3263"]}, DOI={10.1021/jo034945l}, abstractNote={Synthetic molecules bearing phosphonic acid groups can be readily attached to oxide surfaces. As part of a program in molecular-based information storage, we have developed routes for the synthesis of diverse porphyrinic compounds bearing phenylphosphonic acid tethers. The routes enable (1) incorporation of masked phosphonic acid groups in precursors for use in the rational synthesis of porphyrinic compounds and (2) derivatization of porphyrins with masked phosphonic acid groups. The precursors include dipyrromethanes, monoacyldipyrromethanes, and diacyldipyrromethanes. The tert-butyl group has been used to mask the dihydroxyphosphoryl substituent. The di-tert-butyloxyphosphoryl unit is stable to the range of conditions employed in syntheses of porphyrins and multiporphyrin arrays yet can be deprotected under mild conditions (TMS-Cl/TEA or TMS-Br/TEA in refluxing CHCl(3)) that do not cause demetalation of zinc or magnesium porphyrins. The porphyrinic compounds that have been prepared include (1) A(3)B-, trans-AB(2)C-, and ABCD-porphyrins that bear a single phenylphosphonic acid group, (2) a trans-A(2)B(2)-porphyrin bearing two phenylphosphonic acid groups, (3) a chlorin that bears a single phenylphosphonic acid group, and (4) a porphyrin dyad bearing a single phenylphosphonic acid group. For selected porphyrin-phosphonic acids, the electrochemical characteristics have been investigated for molecules tethered to SiO(2) surfaces grown on doped Si. The voltammetric behavior indicates that the porphyrin-phosphonic acids form robust, electrically well-behaved monolayers on the oxide surface.}, number={5}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Muthukumaran, K and Loewe, RS and Ambroise, A and Tamaru, SI and Li, QL and Mathur, G and Bocian, DF and Misra, V and Lindsey, JS}, year={2004}, month={Mar}, pages={1444–1452} }
 @article{loewe_ambroise_muthukumaran_padmaja_lysenko_mathur_li_bocian_misra_lindsey_2004, title={Porphyrins bearing mono or tripodal benzylphosphonic acid tethers for attachment to oxide surfaces}, volume={69}, ISSN={["1520-6904"]}, DOI={10.1021/jo034946d}, abstractNote={The ability to attach redox-active molecules to oxide surfaces in controlled architectures (distance, orientation, packing density) is essential for the design of a variety of molecular-based information storage devices. We describe the synthesis of a series of redox-active molecules wherein each molecule bears a benzylphosphonic acid tether. The redox-active molecules include zinc porphyrins, a cobalt porphyrin, and a ferrocene-zinc porphyrin. An analogous tripodal tether has been prepared that is based on a tris[4-(dihydroxyphosphorylmethyl)phenyl]-derivatized methane. A zinc porphyrin is linked to the methane vertex by a 1,4-phenylene unit. The tripodal systems are designed to improve monolayer stability and ensure vertical orientation of the redox-active porphyrin on the electroactive surface. For comparison purposes, a zinc porphyrin bearing a hexylphosphonic acid tether also has been prepared. The synthetic approaches for introduction of the phosphonic acid group include derivatization of a bromoalkyl porphyrin or use of a dimethyl or diethyl phosphonate substituted precursor in a porphyrin-forming reaction. The latter approach makes use of dipyrromethane building blocks bearing mono or tripodal dialkyl phosphonate groups. The zinc porphyrin-tripodal compound bearing benzylphosphonic acid legs tethered to a SiO(2) surface (grown on doped Si) was electrically well-behaved and exhibited characteristic porphyrin oxidation/reduction waves. Collectively, a variety of porphyrinic molecules can now be prepared with tethers of different length, composition, and structure (mono or tripodal) for studies of molecular-based information storage on oxide surfaces.}, number={5}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Loewe, RS and Ambroise, A and Muthukumaran, K and Padmaja, K and Lysenko, AB and Mathur, G and Li, QL and Bocian, DF and Misra, V and Lindsey, JS}, year={2004}, month={Mar}, pages={1453–1460} }
 @article{yasseri_syomin_loewe_lindsey_zaera_bocian_2004, title={Structural and electron-transfer characteristics of O-, S-, and Se-tethered porphyrin monolayers on Si(100)}, volume={126}, ISSN={["0002-7863"]}, DOI={10.1021/ja045243w}, abstractNote={Monolayers of two classes of Zn porphyrins have been prepared and examined on Si(100). These molecules, designated as ZnPBzX− and ZnPCH2X−, contain either a benzyl (−Bz−) or a methylene (−CH2−) unit terminated with a Group VI atom (X = O, S, Se) appended to a meso-position of the porphyrin, with the nonlinking meso-substituents consisting of either mesityl (−Bz− class) or p-tolyl and phenyl (−CH2− class) units. The two series of ZnPBzX− and ZnPCH2X− monolayers on Si(100) were examined using a variety of techniques, including X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and various electrochemical methods. The studies reveal the following characteristics of the ZnPBzX− and ZnPCH2X− monolayers. (1) Surface binding can be readily achieved to Si(100) with both relatively short (−Bz−) and very short (−CH2−) tethers regardless of the nature of the Group VI anchoring atom (O, S, Se). (2) The longer −Bz− tether affords monolayers with the porphyrin ring in a somewhat more upright orientation with respect to the surface than the shorter −CH2− tether. The more upright adsorption geometry of the porphyrins bearing the former type of linker leads to a higher packing density and more homogeneous redox thermodynamics. (3) The kinetics of electron transfer does not depend on the type of Group VI atom used for anchoring to the Si(100) surface. On the other hand, the type of linker does affect the electron-transfer rates, with the monolayers bearing the −CH2− linker exhibiting systematically faster rates than those bearing the −Bz− linker. Collectively, the studies reported herein provide a detailed picture of how the anchor atom and the linker type influence the structural and electron-transfer characteristics of these general classes of monolayers.}, number={47}, journal={JOURNAL OF THE AMERICAN CHEMICAL SOCIETY}, author={Yasseri, AA and Syomin, D and Loewe, RS and Lindsey, JS and Zaera, F and Bocian, DF}, year={2004}, month={Dec}, pages={15603–15612} }
 @article{liu_yasseri_loewe_lysenko_malinovskii_zhao_surthi_li_misra_lindsey_et al._2004, title={Synthesis of porphyrins bearing hydrocarbon tethers and facile covalent attachment to Si(100)}, volume={69}, ISSN={["0022-3263"]}, DOI={10.1021/jo049439q}, abstractNote={The use of redox-active molecules as the active storage elements in memory chips requires the ability to attach the molecules to an electroactive surface in a reliable and robust manner. To explore the use of porphyrins tethered to silicon via carbosilane linkages, 17 porphyrins have been synthesized. Fourteen porphyrins bear a tether at a single meso site, and three porphyrins bear functional groups at two beta sites for possible two-point attachment. Two high-temperature processing methods (400 degrees C under inert atmosphere) have been developed for rapid (minutes), facile covalent attachment to Si platforms. The high-temperature processing conditions afford attachment either by direct deposition of a dilute solution (1 microM-1 mM) of the porphyrin sample onto the Si substrate or sublimation of a neat sample onto the Si substrate. The availability of this diverse collection of porphyrins enables an in-depth examination of the effects of the tether (length, composition, terminal functional group, number of tethers) and steric bulk of nonlinking substituents on the information-storage properties of the porphyrin monolayers obtained upon attachment to silicon. Attachment proceeds readily with a wide variety of hydrocarbon tethers, including 2-(trimethylsilyl)ethynyl, vinyl, allyl, or 3-butenyl directly appended to the porphyrin and iodo, bromomethyl, 2-(trimethylsilyl)ethynyl, ethynyl, vinyl, or allyl appended to the 4-position of a meso-phenyl ring. No attachment occurs with substituents such as phenyl, p-tolyl, mesityl, or ethyl. Collectively, the studies show that the high-temperature attachment procedure (1) has broad scope encompassing diverse functional groups, (2) tolerates a variety of arene substituents, and (3) does not afford indiscriminate attachment. The high-temperature processing conditions are ideally suited for use in fabrication of hybrid molecular/semiconductor circuitry.}, number={17}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Liu, ZM and Yasseri, AA and Loewe, RS and Lysenko, AB and Malinovskii, VL and Zhao, Q and Surthi, S and Li, QL and Misra, V and Lindsey, JS and et al.}, year={2004}, month={Aug}, pages={5568–5577} }
 @misc{lindsey_loewe_2003, title={Convergent synthesis of multiporphyrin light-harvesting rods}, volume={6,603,070}, number={2003 Aug. 5}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Lindsey, J. S. and Loewe, R. S.}, year={2003} }
 @article{tomizaki_thamyongkit_loewe_lindsey_2003, title={Practical synthesis of perylene-monoimide building blocks that possess features appropriate for use in porphyrin-based light-harvesting arrays}, volume={59}, ISSN={["0040-4020"]}, DOI={10.1016/S0040-4020(03)00020-6}, abstractNote={Perylene-monoimide dyes with solubilizing aryloxy substituents at the perylene perimeter and a synthetic handle on the N-aryl group are valuable building blocks for incorporation as accessory pigments in porphyrin-based light-harvesting arrays. A family of such dyes has been prepared by reaction of 1,6,9-tris(4-tert-butylphenoxy)perylene-3,4-dicarboxylic anhydride with a set of 4-iodo/ethynyl anilines (with or without 2,6-diisopropyl substituents) in the presence of Zn(OAc)2·2H2O in imidazole/mesitylene at 130°C. The workup procedures throughout the synthesis have been streamlined for scale-up purposes, minimizing chromatography. Two bis(perylene)porphyrin building blocks were prepared in a rational manner and examined in Sonogashira and Glaser polymerizations. The two isopropyl groups on the N-aryl group and the three 4-tert-butylphenoxy groups at the perylene perimeter are essential for high solubility of the bis(perylene)porphyrins and corresponding oligomers in organic solvents.}, number={8}, journal={TETRAHEDRON}, author={Tomizaki, KY and Thamyongkit, P and Loewe, RS and Lindsey, JS}, year={2003}, month={Feb}, pages={1191–1207} }
 @article{muthukumaran_loewe_kirmaier_hindin_schwartz_sazanovich_diers_bocian_holten_lindsey_2003, title={Synthesis and excited-state photodynamics of a perylene-monoimide-oxochlorin dyad. A light-harvesting array}, volume={107}, ISSN={["1520-6106"]}, DOI={10.1021/jp026941a}, abstractNote={A perylene-oxochlorin dyad has been prepared and characterized for potential use as a new light-harvesting motif. The dyad (PMI−ZnO) consists of a perylene-monoimide dye (PMI) joined at the 5-position of a zinc oxochlorin (ZnO) via a diphenylethyne linker. The dyad and its subunits have been studied in both polar and nonpolar media using static and time-resolved optical spectroscopy and electrochemical techniques. Energy flows very rapidly from both unrelaxed (vibrationally, conformationally, or electronically) and relaxed forms of the excited perylene (PMI*) to the ground-state oxochlorin with an effective time constant of ∼4 ps and an efficiency of 99% in both toluene and benzonitrile. Subsequently, there is little or no quenching of the excited oxochlorin (ZnO*) in either solvent. These findings are consistent with the expectation that all charge-separated states such as PMI- ZnO+ lie energetically above both PMI* and ZnO* in both polar and nonpolar media. Furthermore, light absorption by the perylene ...}, number={15}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Muthukumaran, K and Loewe, RS and Kirmaier, C and Hindin, E and Schwartz, JK and Sazanovich, IV and Diers, JR and Bocian, DF and Holten, D and Lindsey, JS}, year={2003}, month={Apr}, pages={3431–3442} }
 @article{loewe_lammi_diers_kirmaier_bocian_holten_lindsey_2002, title={Design and synthesis of light-harvesting rods for intrinsic rectification of the migration of excited-state energy and ground-state holes}, volume={12}, ISSN={["0959-9428"]}, DOI={10.1039/b108168c}, abstractNote={We present the design of molecular materials for ultimate use in solid-state solar cells. The molecular materials are semi-rigid oligomeric rods of defined length with metalloporphyrins in the backbone and a carboxy group at one end for attachment to a surface. The rods are designed to absorb visible light, and then undergo excited-state energy transfer and ground-state hole transfer in opposite directions along the length of the rod. The rational synthesis of the multiporphyrin arrays relies on joining porphyrin building blocks in an efficient and controlled manner. Several porphyrin building blocks have been synthesized that bear bromophenyl, iodophenyl, trimethylsilylethynylphenyl and/or ethynylphenyl substituents for use in a copper-free Sonogashira reaction using Pd2(dba)3 and P(o-tol)3. Competition experiments performed on equimolar quantities of an iodo-porphyrin and a bromo-porphyrin with an ethynyl-porphyrin 
show iodo + ethyne coupling with a low amount (35 °C) or undetectable amount (22 °C) of bromo + ethyne coupling. Efficient coupling of bromo-porphyrins with ethynyl-porphyrins was achieved using the same copper-free Sonogashira reaction conditions at higher temperature (50 °C or 80 °C). These findings allow successive coupling reactions to be achieved using substrates bearing iodo and bromo synthetic handles. Thus, a porphyrin-based tetrad (or pentad) was synthesized with a final convergent coupling of a bromo-substituted dyad (or triad) and an ethynyl-substituted dyad. A porphyrin triad was prepared by sequential iodo + ethyne coupling reactions. The triad, tetrad, and pentad each are comprised of a terminal magnesium porphyrin bearing one carboxy group (for surface attachment) and two pentafluorophenyl groups; the remaining porphyrins in each array are present as the zinc chelate. Electrochemical 
characterization of benchmark porphyrins indicates the presence of the desired electrochemical gradient for hole hopping in the arrays. Static absorption data indicate that the arrays are weakly coupled, while static fluorescence data indicate that the excited-state energy flows in high yield to the terminal magnesium porphyrin. Time-resolved spectroscopic analysis leads to rate constants in THF of (9 ps)−1, (15 ps)−1, and (30 ps)−1 for ZnMg dyad 20, Zn2Mg triad 13, and Zn3Mg tetrad 15, respectively, and quantum efficiencies ≥99% for energy flow to the magnesium porphyrin in each case. These design and synthesis strategies should be useful for the construction of materials for molecular-based solar cells.}, number={5}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Loewe, RS and Lammi, RK and Diers, JR and Kirmaier, C and Bocian, DF and Holten, D and Lindsey, JS}, year={2002}, pages={1530–1552} }
 @article{tomizaki_loewe_kirmaier_schwartz_retsek_bocian_holten_lindsey_2002, title={Synthesis and photophysical properties of light-harvesting arrays comprised of a porphyrin bearing multiple perylene-monoimide accessory pigments}, volume={67}, ISSN={["1520-6904"]}, DOI={10.1021/jo0258002}, abstractNote={We present the synthesis and characterization of new light-harvesting arrays containing two, four, or eight perylene-monoimide accessory pigments attached to a zinc porphyrin. Each perylene is substituted with one or three 4-tert-butylphenoxy substituents. A 4,3'- or 4,2'-diarylethyne linker joins the perylene N-imide position and the porphyrin meso-position, affording divergent or convergent architectures, respectively. The architectures are designed to provide high solubility in organic media and facile perylene-to-porphyrin energy transfer, while avoiding charge-transfer quenching of the excited porphyrin product. For the array containing four perylenes per porphyrin in both nonpolar (toluene) and polar (benzonitrile) media and for the array containing eight perylenes per porphyrin in toluene, the photoexcited perylene-monoimide dye (PMI) decays rapidly ( approximately 3.5 ps) and predominantly (>or=90%) by energy transfer to the zinc porphyrin to form the excited zinc porphyrin (Zn), which has excited-state characteristics (lifetime, fluorescence yield) comparable (within approximately 10%) to those of the isolated chromophore. For the array containing eight perylenes in benzonitrile, PMI decays approximately 80% by energy transfer (forming Zn) and approximately 20% by hole transfer (forming PMI- Zn+); Zn subsequently decays approximately 20% by electron transfer (also forming PMI- Zn+) and approximately 80% by the normal routes open to the porphyrin monomer (intersystem crossing, internal conversion, fluorescence). In addition to rapid and efficient perylene-to-porphyrin energy transfer, the broad blue-green to yellow absorption of the perylene dyes complements the blue absorption of the porphyrin, resulting in excellent light harvesting across a significant spectral region. Collectively, the work described herein identifies multiperylene-porphyrin arrays that exhibit suitable photochemical properties for use as motifs in larger light-harvesting systems.}, number={18}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Tomizaki, K and Loewe, RS and Kirmaier, C and Schwartz, JK and Retsek, JL and Bocian, DF and Holten, D and Lindsey, JS}, year={2002}, month={Sep}, pages={6519–6534} }
 @article{loewe_tomizaki_youngblood_bo_lindsey_2002, title={Synthesis of perylene-porphyrin building blocks and rod-like oligomers for light-harvesting applications}, volume={12}, ISSN={["1364-5501"]}, DOI={10.1039/b205680a}, abstractNote={We present the synthesis of four perylene–porphyrin building blocks for use in Glaser, Sonogashira, or Suzuki polymerizations. The building blocks bear synthetic handles (4-ethynylphenyl, 4-iodophenyl, bromo) at the trans 
(5,15) 
meso-positions of a zinc porphyrin and contain two or four perylene-monoimide dyes attached at the 3,5-positions of the non-linking meso-aryl rings of the porphyrin. Each perylene-monoimide bears three 4-tert-butylphenoxy substituents (at the 1-, 6-, and 9-positions) and two isopropyl groups (on the N-aryl unit) for increased solubility. In each case the intervening linker is a diarylethyne unit that bridges the N-imide position of the perylene and the meso-position of the porphyrin. The perylene–porphyrin building blocks were prepared by (1) reaction of a diperylene-dipyrromethane with an aldehyde yielding a trans-A2B2-porphyrin, (2) reaction of a diperylene-aldehyde with a dipyrromethane yielding a trans-A2B2-porphyrin, and (3) reaction of a diperylene-dipyrromethane with a dipyrromethane-dicarbinol yielding a trans-AB2C-porphyrin or ABCD-porphyrin. The building blocks were subjected to Glaser, Sonogashira, or Suzuki coupling conditions in an effort to prepare oligomers containing porphyrins joined via 4,4′-diphenylbutadiyne (dpb), 4,4′-diphenylethyne (dpe), or 1,4-phenylene linkers (p), respectively. Each porphyrin in the backbone bears two or four pendant perylene-monoimide dyes. The Glaser and Sonogashira reactions afforded a distribution of oligomers, whereas the Suzuki reaction was unsuccessful. The oligomers were soluble in solvents such as toluene, THF, or CHCl3 enabling routine handling. The use of perylenes results in (1) increased light-harvesting efficiency particularly in the green spectral region where porphyrins are relatively transparent and (2) greater solubility than is achieved with the use of porphyrins alone. The soluble perylene–porphyrin oligomers are attractive for use as light-harvesting materials in molecular-based solar cells.}, number={12}, journal={JOURNAL OF MATERIALS CHEMISTRY}, author={Loewe, RS and Tomizaki, K and Youngblood, WJ and Bo, ZS and Lindsey, JS}, year={2002}, pages={3438–3451} }
 @article{loewe_tomizaki_chevalier_lindsey_2002, title={Synthesis of perylene-porphyrin dyads for light-harvesting studies}, volume={6}, ISSN={["1099-1409"]}, DOI={10.1142/S1088424602000774}, abstractNote={The spectral coverage of porphyrin-based light-harvesting arrays can be enhanced through the use of suitable accessory pigments. Perylene-monoimide dyes can serve as valuable accessory pigments with porphyrins. To investigate the choice of perylene-monoimide and the effects of molecular architecture on light-harvesting efficacy, five perylene-porphyrin dyads were prepared. Each dyad employs a diphenylethyne linker that bridges the perylene N-imide site and the porphyrin meso-position. Three dyads incorporate a mono-phenoxy perylene at the o-, m-, or p-position of the meso-aryl group on the porphyrin. The two remaining dyads incorporate a perylene-monoimide (bearing zero or three phenoxy substituents) at the p-position of the meso-aryl group on the porphyrin. The introduction of phenoxy groups on the perylenes increases the solubility, a key requirement for use in light-harvesting arrays. The long-wavelength absorption band of the perylene shifts from 506 nm to 532 or 533 nm upon substitution with one or three phenoxy groups, respectively. The synthesis of the dyads entails Pd-mediated coupling of a bromo-perylene and an ethynyl porphyrin, or the mixed-aldehyde condensation with a perylene-aldehyde, mesitaldehyde, and pyrrole. Five perylene-monoimide dyes bearing an ethyne or bromo substituent at the p-position of the N-aryl unit were developed for this modular chemistry. Each perylene-porphyrin dyad exhibits efficient energy transfer from the excited perylene to the ground-state porphyrin.}, number={9-10}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, author={Loewe, RS and Tomizaki, KY and Chevalier, F and Lindsey, JS}, year={2002}, pages={626–642} }
 @article{ambroise_kirmaier_wagner_loewe_bocian_holten_lindsey_2002, title={Weakly coupled molecular photonic wires: Synthesis and excited-state energy-transfer dynamics}, volume={67}, ISSN={["1520-6904"]}, DOI={10.1021/jo025561i}, abstractNote={Molecular photonic wires, which absorb light and undergo excited-state energy transfer, are of interest as biomimetic models for photosynthetic light-harvesting systems and as molecular devices with potential applications in materials chemistry. We describe the stepwise synthesis of four molecular photonic wires. Each wire consists of an input unit, transmission element, and output unit. The input unit consists of a boron-dipyrrin dye or a perylene-monoimide dye (linked either at the N-imide or the C9 position); the transmission element consists of one or three zinc porphyrins affording short or long wires, respectively; and the output unit consists of a free base (Fb) porphyrin. The components in the arrays are joined in a linear architecture via diarylethyne linkers (an ethynylphenyl linker is attached to the C9-linked perylene). The wires have been examined by static absorption, static fluorescence, and time-resolved absorption spectroscopy. Each wire (with the exception of the C9-linked perylene wire) exhibits a visible absorption spectrum that is the sum of the spectra of the component parts, indicating the relatively weak electronic coupling between the components. Excitation of each wire at the wavelength where the input unit absorbs preferentially (typically 480-520 nm) results in emission almost exclusively from the Fb porphyrin. The static emission and time-resolved data indicate that the overall rate constants and quantum efficiencies for end-to-end (i.e., input to output) energy transfer are as follows: perylene-(N-imide)-linked short wire, (33 ps)(-1) and >99%; perylene-(C9)-linked short wire, (26 ps)(-1) and >99%; boron-dipyrrin-based long wire, (190 ps)(-1) and 81%; perylene-(N-imide)-linked long wire, (175 ps)(-1) and 86%. Collectively, the studies provide valuable insight into the singlet-singlet excited-state energy-transfer properties in weakly coupled molecular photonic wires.}, number={11}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Ambroise, A and Kirmaier, C and Wagner, RW and Loewe, RS and Bocian, DF and Holten, D and Lindsey, JS}, year={2002}, month={May}, pages={3811–3826} }
 @misc{mccullough_loewe_2000, title={Method of forming poly-(3-substituted) thiophenes}, volume={6,166,172}, number={2000 Dec. 26}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={McCullough, R. D. and Loewe, R. S.}, year={2000} }
 @misc{bernacchi_loewe_immel_1991, title={Storage stable, readily reconstituted comestible}, volume={5,008,121}, number={1991 Apr. 16}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bernacchi, D. B. and Loewe, R. J. and Immel, D. L.}, year={1991} }
 @misc{bernacchi_loewe_immel_1990, title={Process for preparing storage stable, readily reconstituted frozen comestibles and frozen comestibles produced thereby}, volume={4,948,603}, number={1990 Aug. 14}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bernacchi, D. B. and Loewe, R. J. and Immel, D. L.}, year={1990} }
 @misc{bernacchi_loewe_1988, title={Process for preparing readily reconstituted frozen comestibles and frozen comestibles produced thereby}, volume={4,744,994}, number={1988 May 17}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bernacchi, D. B. and Loewe, R. J.}, year={1988} }
 @misc{bernacchi_loewe_immel_1988, title={Process for preparing storage stable, readily reconstituted frozen comestibles}, volume={4,764,386}, number={1988 Aug. 16}, publisher={Washington, DC: U.S. Patent and Trademark Office}, author={Bernacchi, D. B. and Loewe, R. J. and Immel, D. L.}, year={1988} }