Chinnasamy Muthiah

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The use of chlorins as photosensitizers or fluorophores in a range of biological applications requires facile provisions for imparting high water solubility. Two free base chlorins have been prepared wherein each chlorin bears a geminal dimethyl group in the reduced ring and a water-solubilizing unit at the chlorin 10-position. In one design (FbC1-PO3H2),(More)
Synthetic chlorins bearing diverse auxochromes at the 3- and 13-positions of the macrocycle are valuable targets given their resemblance to chlorophylls a and b, which bear 3-vinyl and 13-keto groups. A de novo route has been exploited to construct nine zinc chlorins bearing substituents at the 3- and 13-positions and two benchmark zinc chlorins lacking(More)
Understanding the effects of substituents on the spectra of chlorins is essential for a wide variety of applications. Recent developments in synthetic methodology have made possible systematic studies of the properties of the chlorin macrocycle as a function of diverse types and patterns of substituents. In this paper, the spectral, vibrational and(More)
Chlorophyll a and chlorophyll b exhibit distinct spectra yet differ only in the nature of a single substituent (7-methyl versus 7-formyl, respectively). Two complementary approaches have been developed for the synthesis of 7-substituted chlorins. The first approach is a de novo route wherein 2,9-dibromo-5-p-tolyldipyrromethane (Eastern half) and(More)
Two distinct approaches have been developed for the synthesis of chlorins bearing formyl groups: (1) reaction of an acetal-substituted 1-acyldipyrromethane with 2,3,5,6-tetrahydro-1,3,3-trimethyldipyrrin to give upon hydrolysis a 5-formylchlorin and (2) Pd-mediated coupling of a bromochlorin with a one-carbon synthon (hydroxymethyl tributyltin or CO) to(More)
The ability to introduce substituents at designated sites about the perimeter of the chlorin or 13(1)-oxophorbine macrocycle is essential for fundamental studies related to chlorophylls. A chlorin is a dihydroporphyrin, whereas a 13(1)-oxophorbine is a chlorin containing an annulated oxopentano ring spanning positions 13 and 15. 13(1)-Oxophorbines bearing(More)
The photophysical properties of two energy-transfer dyads that are potential candidates for near-infrared (NIR) imaging probes are investigated as a function of solvent polarity. The dyads (FbC-FbB and ZnC-FbB) contain either a free base (Fb) or zinc (Zn) chlorin (C) as the energy donor and a free base bacteriochlorin (B) as the energy acceptor. The dyads(More)
The ability to tailor synthetic porphyrin, chlorin and bacteriochlorin molecules holds promise for diverse studies in artificial photosynthesis. Toward this goal, the synthesis and photophysical characterization of five tetrapyrrole compounds is described. Each compound bears a surface attachment group. One set contains three meso-substituted porphyrins(More)
Assessing the effects of substituents on the spectra of chlorophylls is essential for gaining a deep understanding of photosynthetic processes. Chlorophyll a and b differ solely in the nature of the 7-substituent (methyl versus formyl), whereas chlorophyll a and d differ solely in the 3-substituent (vinyl versus formyl), yet have distinct long-wavelength(More)
A new route to 13(1)-oxophorbines, the parent macrocycle of chlorophylls, begins with the synthesis of a 13-bromochlorin. Pd-mediated coupling of the latter with tributyl(1-ethoxyvinyl)tin and subsequent acidic hydrolysis afforded the 13-acetylchlorin (1). Treatment of 1 with NBS afforded the 15-bromo analogue in 70% yield. Pd-mediated alpha-arylation(More)