@article{lindsey_thamyongkit_taniguchi_bocian_2011, title={Encoding isotopic watermarks in molecular electronic materials as an anti-counterfeiting strategy. Application to porphyrins for information storage}, volume={15}, ISSN={["1099-1409"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-80051761959&partnerID=MN8TOARS}, DOI={10.1142/s1088424611003458}, abstractNote={An approach for information storage employs tetrapyrrole macrocycles as charge-storage elements attached to a (semi)conductor in hybrid chips. Anti-counterfeiting measures must cohere with the tiny amounts of such electroactive material and strict constraints on composition in chips; accordingly, the incorporation of typical anti-counterfeiting taggants or microcarriers is precluded. The provenance of the tetrapyrroles can be established through the use of isotopic substitution integral to the macrocycle. The isotopic substitution can be achieved by rational site-specific incorporation or by combinatorial procedures. The formation of a mixture of such macrocycles with various isotopic composition (isotopically unmodified, isotopologues, isotopomers) provides the molecular equivalent of an indelible printed watermark. Resonance Raman spectroscopic examination can reveal the watermark, but not the underlying molecular and isotopic composition; imaging mass spectrometry can reveal the presence of isotopologues but cannot discriminate among isotopomers. Hence, deciphering the code that encrypts the watermark in an attempt at forgery is expected to be prohibitive. A brief overview is provided of strategies for incorporating isotopes in meso-substituted tetrapyrrole macrocycles.}, number={7-8}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, publisher={World Scientific Pub Co Pte Lt}, author={Lindsey, Jonathan S. and Thamyongkit, Patchanita and Taniguchi, Masahiko and Bocian, David F.}, year={2011}, pages={505–516} }
 @article{muresan_thamyongkit_diers_holten_lindsey_bocian_2008, title={Regiospecifically alpha-C-13-labeled porphyrins for studies of ground-state hole transfer in multiporphyrin arrays}, volume={73}, ISSN={["0022-3263"]}, DOI={10.1021/jo8012836}, abstractNote={Insight into the electronic communication between the individual constituents of multicomponent molecular architectures is essential for the rational design of molecular electronic and/or photonic devices. To clock the ground-state hole/electron-transfer process in oxidized multiporphyrin architectures, a p-diphenylethyne-linked zinc porphyrin dyad was prepared wherein one porphyrin bears two (13)C atoms and the other porphyrin is unlabeled. The (13)C atoms are located at the 1- and 9-positions (alpha-carbons symmetrically disposed to the position of linker attachment), which are sites of electron/spin density in the a(1u) HOMO of the porphyrin. The (13)C labels were introduced by reaction of KS(13)CN with allyl bromide to give the allyl isothiocyanate, which upon Trofimov pyrrole synthesis followed by methylation gave 2-(methylthio)pyrrole-2-(13)C. Reaction of the latter with paraformaldehyde followed by hydrodesulfurization gave dipyrromethane-1,9-(13)C, which upon condensation with a dipyrromethane-1,9-dicarbinol bearing three pentafluorophenyl groups gave the tris(pentafluorophenyl)porphyrin bearing (13)C labels at the 1,9-positions and an unsubstituted meso (5-) position. Zinc insertion, bromination at the 5-position, and Suzuki coupling with an unlabeled porphyrin bearing a suitably functionalized diphenylethyne linker gave the regiospecifically labeled zinc porphyrin dyad. Examination of the monocation of the isotopically labeled dyad via electron paramagnetic resonance (EPR) spectroscopy (and comparison with the monocations of benchmark monomers, where hole transfer cannot occur) showed that the hole transfer between porphyrin constituents of the dyad is slow (<10(6) s(-1)) on the EPR time scale at room temperature. The slow rate stems from the a(1u) HOMO of the electron-deficient porphyrins, which has a node at the site of linker connection. In contrast, analogous dyads of electron-rich porphyrins (wherein the HOMO is a(2u) and has a lobe at the site of linker connection) studied previously exhibit rates of hole transfer that are fast (>5 x 10(7) s(-1)) on the EPR time scale at room temperature.}, number={18}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Muresan, Ana Z. and Thamyongkit, Patchanita and Diers, James R. and Holten, Dewey and Lindsey, Jonathan S. and Bocian, David F.}, year={2008}, month={Sep}, pages={6947–6959} }
 @article{jiao_thamyongkit_schmidt_lindsey_bocian_2007, title={Characterization of porphyrin surface orientation in monolayers on au(111) and si(100) using spectroscopically labeled molecules}, volume={111}, ISSN={["1932-7447"]}, DOI={10.1021/jp073824c}, abstractNote={The synthesis and surface IR characterization are reported for a series of porphyrins bearing vibrational spectroscopic labels that afford distinction of the two in-plane axes of the porphyrin ring. The labeled porphyrins include three different types of tethers for surface attachment, those containing either methylthio (−CH2S−) or benzylthio (−BzS−) for attachment to either Au or Si and a tripodal alkenyl group for attachment to Si. The spectroscopic labels are placed so as to enable distinction between the methyl group of a p-tolyl substituent that lies along the molecular axis distal to the tether versus the p-tolyl substituents that lie along the orthogonal in-plane axis lateral to the tether. The porphyrins include isotopically labeled species containing CD3 and species wherein a CF3 replaces CH3. The spectroscopically labeled molecules allow evaluation of both the tilt angle (θ) with respect to the surface normal and the rotation angle (φ) about the molecular axis. These two angles cannot be uniquel...}, number={34}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, author={Jiao, Jieying and Thamyongkit, Patchanita and Schmidt, Izabela and Lindsey, Jonathan S. and Bocian, David F.}, year={2007}, month={Aug}, pages={12693–12704} }
 @article{thamyongkit_muresan_diers_holten_bocian_lindsey_2007, title={Meso-C-13-labeled porphyrins for studies of ground-state hole transfer in multiporphyrin arrays}, volume={72}, ISSN={["0022-3263"]}, DOI={10.1021/jo070593x}, abstractNote={Understanding electronic communication among interacting chromophores provides the foundation for a variety of applications. The ground-state electronic communication in diphenylethyne-linked zinc-porphyrin dyads has been investigated by a novel molecular design strategy that entails introduction of a 13C-atom (*) at specific sites of the porphyrins where there is substantial electron density in the relevant frontier (highest occupied) molecular orbital. The site of 13C substitution is at a meso-position, either the site of attachment of the linker (proximal, "P") or the site trans to the linker (distal, "D"). The substituents (R) at the non-linking meso-positions are mesityl, tridec-7-yl ("swallowtail"), or p-tolyl groups. Altogether five isotopically labeled porphyrin dyads have been prepared. The hole/electron-transfer properties of one-electron oxidized dyads have been examined by electron paramagnetic resonance (EPR) spectroscopy. The introduction of the meso-13C label provides a "clock" (via the hyperfine interactions) that allows investigation of a time scale for hole transfer that is 3-4 times shorter than that provided by the natural abundance 14N nuclei of the pyrrole nitrogen atoms. The EPR studies indicate that the hole transfer, which has been previously shown to be fast on the time scale of the 14N hyperfine clock ( approximately 220 ns), remains fast on the time scale of the 13C hyperfine clock ( approximately 50 ns).}, number={14}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Thamyongkit, Patchanita and Muresan, Ana Z. and Diers, James R. and Holten, Dewey and Bocian, David F. and Lindsey, Jonathan S.}, year={2007}, month={Jul}, pages={5207–5217} }
 @article{dogutan_zaidi_thamyongkit_lindsey_2007, title={New route to ABCD-porphyrins via bilanes}, volume={72}, ISSN={["1520-6904"]}, DOI={10.1021/jo701294d}, abstractNote={A new strategy for preparing porphyrins that bear up to four different meso-substituents (ABCD-porphyrins) relies on two key reactions. One key reaction entails a directed synthesis of a 1-protected 19-acylbilane by acid-catalyzed condensation at high concentration (0.5 M) of a 1-acyldipyrromethane and a 9-protected dipyrromethane-1-carbinol (derived from a 9-protected 1-acyldipyrromethane). Three protecting groups (X) were examined, including thiocyanato, ethylthio, and bromo, of which bromo proved most effective. The bilanes were obtained in 72-80% yield, fully characterized, and examined by 15N NMR spectroscopy. The second key reaction entails a one-flask transformation of the 1-protected 19-acylbilane under basic, metal-templating conditions to give the corresponding metalloporphyrin. The reaction parameters investigated for cyclization of the bilane include solvent, metal salt, base, concentration, temperature, atmosphere, and time. The best conditions entailed the 1-bromo-19-acylbilane at 100 mM in toluene containing DBU (10 mol equiv) and MgBr2 (3 mol equiv) at 115 degrees C exposed to air for 2 h, which afforded the magnesium porphyrin in 65% yield. The magnesium porphyrin is readily demetalated to give the free base porphyrin. A stepwise procedure (which entailed treatment of the 1-(ethylthio)-19-acylbilane to oxidation, metal complexation, desulfurization, carbonyl reduction, and acid-catalyzed condensation) was developed but was much less efficient than the one-flask process. The new route to ABCD-porphyrins retains the desirable features of the existing "2 + 2" (dipyrromethane + dipyrromethane-1,9-dicarbinol) method, such as absence of scrambling, yet has significant advantages. The advantages include the absence of acid in the porphyrin-forming step, the use of a metal template for cyclization, the ability to carry out the reaction at high concentration, the lack of a quinone oxidant, avoidance of use of dichloromethane, and the increased yield of macrocycle formation to give the target ABCD-metalloporphyrin.}, number={20}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Dogutan, Dilek Kiper and Zaidi, Syeda Huma H. and Thamyongkit, Patchanita and Lindsey, Jonathan S.}, year={2007}, month={Sep}, pages={7701–7714} }
 @article{thamyongkit_bhise_taniguchi_lindsey_2006, title={Alkylthio unit as an alpha-pyrrole protecting group for use in dipyrromethane synthesis}, volume={71}, ISSN={["1520-6904"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-32144435067&partnerID=MN8TOARS}, DOI={10.1021/jo051806q}, abstractNote={The synthesis of porphyrin precursors requires the successive introduction of substituents at the pyrrole α- and α‘-positions (2- and 5-, respectively). An α-pyrrole substituent that serves as a temporary masking agent and is not deactivating would greatly facilitate such syntheses, particularly for β-(3,4)-unsubstituted pyrroles, but has heretofore not been available. A series of α-RS groups (R = Me, Et, n-decyl, Ph) have been investigated in this regard, including the determination of the kinetics of substitution at the pyrrolic 3-, 4-, and 5-positions and the application to dipyrromethane formation. The RS group was readily introduced into the pyrrole α-position by the reaction of 2-thiocyanatopyrrole (prepared from pyrrole, ammonium thiocyanate, and iodine) and the corresponding Grignard reagent RMgBr. Each 2-alkylthio group activated the pyrrole ring toward deuteration at the 3- or 5- (vs 4-) position. The dipyrromethane synthesis was carried out using a 2:1 ratio of 2-(RS)pyrrole/benzaldehyde with a...}, number={3}, journal={JOURNAL OF ORGANIC CHEMISTRY}, publisher={American Chemical Society (ACS)}, author={Thamyongkit, P and Bhise, AD and Taniguchi, M and Lindsey, JS}, year={2006}, month={Feb}, pages={903–910} }
 @article{lysenko_thamyongkit_schmidt_diers_bocian_lindsey_2006, title={Diverse porphyrin dimers as candidates for high-density charge-storage molecules}, volume={10}, ISSN={["1099-1409"]}, DOI={10.1142/S1088424606000041}, abstractNote={ Porphyrinic molecules have been shown to be viable candidates for a molecular-based information storage medium on the basis of redox activity. An optimal redox-based information storage medium requires a large charge density in the molecular footprint on the anchoring substrate. The use of dimeric versus monomeric architectures affords one route to achieving increased charge density without sacrificing surface cross sectional area. Towards this goal, a series of zinc and cobalt containing porphyrin dimers has been prepared and characterized. The interporphyrin linkages in the dimers include p-phenylene, ethynyl, 1,4-butadiynyl, and ethynylphenylethynyl joining porphyrin meso-positions; Crossley-type fusion bridging porphyrin β-positions, and Osuka-type triple fusions bridging one meso- and two β-positions. The electrochemical features of each dimer have been evaluated. }, number={1}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, author={Lysenko, Andrey B. and Thamyongkit, Patchanita and Schmidt, Izabela and Diers, James R. and Bocian, David F. and Lindsey, Jonathan S.}, year={2006}, pages={22–32} }
 @article{schmidt_jiao_thamyongkit_sharada_bocian_lindsey_2006, title={Investigation of stepwise covalent synthesis on a surface yielding porphyrin-based multicomponent architectures}, volume={71}, ISSN={["0022-3263"]}, DOI={10.1021/jo052650x}, abstractNote={Porphyrins have been shown to be a viable medium for use in molecular-based information storage applications. The success of this application requires the construction of a stack of components ("electroactive surface/tether/charge-storage molecule/linker/electrolyte/top contact") that can withstand high-temperature conditions during fabrication (up to 400 degrees C) and operation (up to 140 degrees C). To identify suitable chemistry that enables in situ stepwise synthesis of covalently linked architectures on an electroactive surface, three sets of zinc porphyrins (22 altogether) have been prepared. In the set designed to form the base layer on a surface, each porphyrin incorporates a surface attachment group (triallyl tripod or vinyl monopod) and a distal functional group (e.g., pentafluorophenyl, amine, bromo, carboxy) for elaboration after surface attachment. A second set designed for in situ dyad construction incorporates a single functional group (alcohol, isothiocyanato) that is complementary to the functional group in the base porphyrins. A third set designed for in situ multad construction incorporates two identical functional groups (bromo, alcohol, active methylene, amine, isothiocyanato) in a trans configuration (5,15-positions in the porphyrin). Each porphyrin that bears a surface attachment group was found to form a good quality monolayer on Si(100) as evidenced by the voltammetric and vibrational signatures. One particularly successful chemistry identified for stepwise growth entailed reaction of a surface-tethered porphyrin-amine with a dianhydride (e.g., 3,3',4,4'-biphenyltetracarboxylic dianhydride), forming the monoimide/monoanhydride. Subsequent reaction with a diamine (e.g., 4,4'-methylene-bis(2,6-dimethylaniline)) gave the bis(imide) bearing a terminal amine. Repetition of this stepwise growth process afforded surface-bound oligo-imide architectures composed of alternating components without any reliance on protecting groups. Taken together, the ability to prepare covalently linked constructs on a surface without protecting groups in a stepwise manner augurs well for the systematic preparation of a wide variety of functional molecular devices.}, number={8}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Schmidt, I and Jiao, JY and Thamyongkit, P and Sharada, DS and Bocian, DF and Lindsey, JS}, year={2006}, month={Apr}, pages={3033–3050} }
 @article{thamyongkit_yu_padmaja_jiao_bocian_lindsey_2006, title={Porphyrin dyads bearing carbon tethers for studies of high-density molecular charge storage on silicon surfaces}, volume={71}, ISSN={["1520-6904"]}, DOI={10.1021/jo0522761}, abstractNote={Redox-active molecules that afford high charge density upon attachment to an electroactive surface are of interest for use in molecular-based information-storage applications. One strategy for increasing charge density is to covalently link a second redox center to the first in an architecture that uses the vertical dimension in essentially the same molecular footprint. Toward this end, a set of four new porphyrin dyads have been prepared and characterized. Each dyad consists of two zinc porphyrins, an intervening linker (p-phenylene or 4,4'-diphenylethyne), and a surface attachment group (ethynyl or triallyl group). The porphyrin dyads were attached to an electroactive Si(100) surface and interrogated via electrochemical and FTIR techniques. The charge density obtainable for the ethynyl-functionalized porphyrin dyads is approximately double that observed for an analogously functionalized monomer, whereas that for the triallyl-functionalized dyads is at most 40% larger. These results indicate that the molecular footprint of the former dyads is similar to that of a monomer while that of the latter dyads is larger. For both the ethynyl- and triallyl-functionalized porphyrin dyads, higher charge densities (smaller molecular footprints) are obtained for the molecules containing the 4,4'-diphenylethyne versus the p-phenylene linker. This feature is attributed to the enhanced torsional flexibility of the former linker compared with that of the latter, which affords better packed monolayers. The FTIR studies indicate that the adsorption geometry of all the dyads is qualitatively similar and similar to that of monomers. However, the dyads containing the 4,4'-diphenylethyne linker sit somewhat more upright on the surface than those containing the p-phenylene linker, generally consistent with the smaller molecular footprint for the former dyads. Collectively, the high surface charge density (34-58 muC.cm(-)(2)) of the porphyrin dyads makes these constructs viable candidates for molecular-information-storage applications.}, number={3}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Thamyongkit, P and Yu, LH and Padmaja, K and Jiao, JY and Bocian, DF and Lindsey, JS}, year={2006}, month={Feb}, pages={1156–1171} }
 @article{zou_wei_chen_liu_thamyongkit_loewe_lindsey_mohideen_bocian_2005, title={Solution STM images of porphyrins on HOPG reveal that subtle differences in molecular structure dramatically alter packing geometry}, volume={9}, ISSN={["1099-1409"]}, DOI={10.1142/S1088424605000484}, abstractNote={ Solution STM images are reported for free-base octaethylporphyrin ( H 2 OEP ) and the Cu ( II ) and Zn ( II ) chelates ( CuOEP and ZnOEP ) on HOPG in 1,2-dichlorobenzene solution under ambient conditions. H 2 OEP and CuOEP each form a quasi-square lattice, whereas ZnOEP forms a quasi-hexagonal lattice on the surface. The binary mixture of any two of the porphyrins forms a well-ordered two-layer structure on the HOPG surface, with one species occupying the bridge sites of the array of the other species. All of the mixed adlayers exhibit a quasi-hexagonal lattice with a higher packing density than the single-component adlayers. Collectively, these observations indicate that the structure of the adlayers is controlled by a complex interplay of substrate-molecule and molecule-molecule interactions. }, number={6}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, author={Zou, ZQ and Wei, LY and Chen, F and Liu, ZM and Thamyongkit, P and Loewe, RS and Lindsey, JS and Mohideen, U and Bocian, DF}, year={2005}, pages={387–392} }
 @article{kee_kirmaier_yu_thamyongkit_youngblood_calder_ramos_noll_bocian_scheidt_et al._2005, title={Structural control of the photodynamics of boron-dipyrrin complexes}, volume={109}, ISSN={["1520-5207"]}, DOI={10.1021/jp0525078}, abstractNote={Boron-dipyrrin chromophores containing a 5-aryl group with or without internal steric hindrance toward aryl rotation have been synthesized and then characterized via X-ray diffraction, static and time-resolved optical spectroscopy, and theory. Compounds with a 5-phenyl or 5-(4-tert-butylphenyl) group show low fluorescence yields (approximately 0.06) and short excited-singlet-state lifetimes (approximately 500 ps), and decay primarily (>90%) by nonradiative internal conversion to the ground state. In contrast, sterically hindered analogues having an o-tolyl or mesityl group at the 5-position exhibit high fluorescence yields (approximately 0.9) and long excited-state lifetimes (approximately 6 ns). The X-ray structures indicate that the phenyl or 4-tert-butylphenyl ring lies at an angle of approximately 60 degrees with respect to the dipyrrin framework whereas the angle is approximately 80 degrees for mesityl or o-tolyl groups. The calculated potential energy surface for the phenyl-substituted complex indicates that the excited state has a second, lower energy minimum in which the nonhindered aryl ring rotates closer to the mean plane of the dipyrrin, which itself undergoes some distortion. This relaxed, distorted excited-state conformation has low radiative probability as well as a reduced energy gap from the ground state supporting a favorable vibrational overlap factor for nonradiative deactivation. Such a distorted conformation is energetically inaccessible in a complex bearing the sterically hindered o-tolyl or mesityl group at the 5-position, leading to a high radiative probability involving conformations at or near the initial Franck-Condon form of the excited state. These combined results demonstrate the critical role of aryl-ring rotation in governing the excited-state dynamics of this class of widely used dyes.}, number={43}, journal={JOURNAL OF PHYSICAL CHEMISTRY B}, author={Kee, HL and Kirmaier, C and Yu, LH and Thamyongkit, P and Youngblood, WJ and Calder, ME and Ramos, L and Noll, BC and Bocian, DF and Scheidt, WR and et al.}, year={2005}, month={Nov}, pages={20433–20443} }
 @article{liu_schmidt_thamyongkit_loewe_syomin_diers_zhao_misra_lindsey_bocian_2005, title={Synthesis and Film-Forming Properties of Ethynylporphyrins}, volume={17}, ISSN={0897-4756 1520-5002}, url={http://dx.doi.org/10.1021/cm047858y}, DOI={10.1021/cm047858y}, abstractNote={Thermal treatment of ethynyl porphyrin monomers on a surface has been found to yield robust porphyrin films. The scope of this in situ polymerization has been surveyed by the synthesis and characterization of a collection of 20 zinc porphyrins bearing diverse patterns of 1−4 ethyne (or protected ethyne) groups and a variety of nonlinking substituents. Films have been prepared on Si(100), SiO2, Au(111), and glass. The films prepared on Si(100) have been examined by electrochemical methods, which indicate that surface coverages 50-fold greater than those of saturation-coverage monolayers are achievable, although the coverage varies appreciably (10-fold) among the survey group of molecules under a controlled set of film-forming conditions. Variation in these conditions affords control over the number of layers in the film (from a few to tens or more). The electrochemical characteristics of the multilayer films further indicate that the redox thermodynamics are of comparable homogeneity to those of monolayers...}, number={14}, journal={Chemistry of Materials}, publisher={American Chemical Society (ACS)}, author={Liu, Zhiming and Schmidt, Izabela and Thamyongkit, Patchanita and Loewe, Robert S. and Syomin, Dennis and Diers, James R. and Zhao, Qian and Misra, Veena and Lindsey, Jonathan S. and Bocian, David F.}, year={2005}, month={Jul}, pages={3728–3742} }
 @article{muthukumaran_zaidi_yu_thamyongkit_calder_sharada_lindsey_2005, title={Synthesis of dipyrrin-containing architectures}, volume={9}, ISSN={["1099-1409"]}, DOI={10.1142/S108842460500085X}, abstractNote={ Dipyrrins are valuable precursors to dyes [dipyrrinatoboron difluoride, bis(dipyrrinato)-zinc(II) complexes] and serve as ligands in a variety of self-assembled materials. Six new dipyrrin-containing architectures have been synthesized. The architectures include bis(dipyrrinato) complexes containing copper(II) or palladium(II), a dipyrrin bearing a protected phosphonic acid unit, a porphyrin bearing two dipyrrins in a trans configuration, a linear diphenylethyne-linked dipyrromethane-dipyrrin building block, and a triad composed of two zinc porphyrins joined via an intervening bis(dipyrrinato)copper(II) complex. Two porphodimethenatozinc complexes were prepared and found to have Φ f  ≤ 0.002 (in toluene at room temperature), which is substantially less than the analogous bis(dipyrrinato)zinc complexes. Taken together, the syntheses described herein should broaden access to dipyrrins for use as complexation motifs in supramolecular chemistry and as pigments in light-harvesting applications. }, number={10-11}, journal={JOURNAL OF PORPHYRINS AND PHTHALOCYANINES}, author={Muthukumaran, Kannan and Zaidi, Syeda Huma H. and Yu, Lianhe and Thamyongkit, Patchanita and Calder, Matthew E. and Sharada, Duddu S. and Lindsey, Jonathan S.}, year={2005}, pages={745–759} }
 @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{thamyongkit_speckbacher_diers_kee_kirmaier_holten_bocian_lindsey_2004, title={Swallowtail porphyrins: Synthesis, characterization and incorporation into porphyrin dyads}, volume={69}, ISSN={["1520-6904"]}, DOI={10.1021/jo049860e}, abstractNote={The incorporation of symmetrically branched tridecyl ("swallowtail") substituents at the meso positions of porphyrins results in highly soluble building blocks. Synthetic routes have been investigated to obtain porphyrin building blocks bearing 1-4 swallowtail groups. Porphyrin dyads have been synthesized in which the zinc or free base (Fb) porphyrins are joined by a 4,4'-diphenylethyne linker and bear swallowtail (or n-pentyl) groups at the nonlinking meso positions. The swallowtail-substituted Zn(2)- and ZnFb-dyads are readily soluble in common organic solvents. Static absorption and fluorescence spectra and electrochemical data show that the presence of the swallowtail groups slightly raises the energy level of the filled a(2u)(pi) HOMO. EPR studies of the pi-cation radicals of the swallowtail porphyrins indicate that the torsional angle between the proton on the alkyl carbon and p-orbital on the meso carbon of the porphyrin is different from that of a porphyrin bearing linear pentyl groups. Regardless, the swallowtail substituents do not significantly affect the photophysical properties of the porphyrins or the electronic interactions between the porphyrins in the dyads. In particular, time-resolved spectroscopic studies indicate that facile excited-state energy transfer occurs in the ZnFb dyad, and EPR studies of the monocation radical of the Zn(2)-dyad show that interporphyrin ground-state hole transfer is rapid.}, number={11}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Thamyongkit, P and Speckbacher, M and Diers, JR and Kee, HL and Kirmaier, C and Holten, D and Bocian, DF and Lindsey, JS}, year={2004}, month={May}, pages={3700–3710} }
 @article{thamyongkit_lindsey_2004, title={Synthesis of swallowtail-substituted multiporphyrin rods}, volume={69}, ISSN={["0022-3263"]}, DOI={10.1021/jo049348t}, abstractNote={The availability of multiporphyrin arrays with defined architectures and good solubility in organic solvents is essential for a wide variety of physical studies. Herein the synthesis of linear multiporphyrin arrays (triads, tetrad, pentad) bearing solubilizing 7-tridecyl (swallowtail) groups is presented. The rodlike arrays are composed of zinc porphyrins at the termini and 1, 2, or 3 free base porphyrins at the core. The free base porphyrins in the tetrad and pentad are joined to each other via p-phenylene linkers whereas the zinc porphyrins in each array are attached to the core free base porphyrins via 1,4-diphenylethyne linkers. The arrays are designed for studies of interporphyrin electronic communication.}, number={17}, journal={JOURNAL OF ORGANIC CHEMISTRY}, author={Thamyongkit, P and Lindsey, JS}, year={2004}, month={Aug}, pages={5796–5799} }