Thiaporphyrins: from building blocks to multiporphyrin arrays

Abstract

Thiaporphyrins and 21,23-dithiaporphyrins resulting from the replacement of one and two pyrrole rings respectively, of tetrapyrrolic porphyrins possess singlet state energy levels which are lower than porphyrins and metalloporphyrins. This specific feature of thiaporphyrins is advantageous when thiaporphyrins are connected either covalently or non-covalently to porphyrins and metalloporphyrins for unidirectional flow of energy transfer/electron transfer. In recent times, the synthetic routes were developed for the synthesis of functionalized thiaporphyrin building blocks which were not accessible earlier. The functionalized thiaporphyrins have been used to synthesize several unsymmetrical thiaporphyrin-based arrays containing two or more different types of porphyrin subunits whose singlet state energy levels are arranged in a favourable way for the energy transfer/electron transfer. In this review, we describe different synthetic approaches being employed for the synthesis of functionalized thiaporphyrin building blocks and their use in the construction of several covalently and non-covalently linked thiaporphyrinbased multiporphyrin arrays ranging from dyads to octads. The photophysical studies are also described to show the possibility of singlet-singlet energy transfer from one porphyrin unit to another in some selected thiaporphyrin-based multiporphyrin arrays. Yogita Pareek was born inRajasthan in 1983. She received her B.Sc. and M.Sc. from Rajasthan University. In 2009, she joined as a Ph.D. student in Indian Institute of Technology Bombay under supervision of professor M. Ravikanth, and recently she obtained her Ph.D. degree. Currently she is working as a research scientist for Applied Materials Inc. Mumbai, India. M. Ravikanth was born in Andhra Pradesh, in 1966. He received his B.Sc. and M.Sc. from Osmania University, Hyderabad and Ph.D. from Indian Institute of Technology Kanpur in 1994. Aer his postdoctoral stay in the USA and Japan, he joined as a faculty member at Indian Institute of Technology Bombay, where he is currently working as a full professor. His current research interests include porphyrins and related macrocycles.

Synthesis, Structural, Spectral, and Electrochemical Studies of Selenabenziporphyrin and Its Pd(II) Complex

“…The core-modified porphyrins or heteroporphyrins possess very interesting physicochemical properties that are quite different from regular tetrapyrrolic porphyrins . Several covalently and noncovalently linked heteroporphyrin-based multiporphyrin arrays were synthesized, and their properties were explored . New heterocorroles, heterocalix[4]­phyrins, and metal derivatives of heteroporphyrins were synthesized and characterized. , During our course of investigations, we realized that the reports on the heterobenziporphyrins, which are a subclass of benziporphyrins in which one of the pyrrole rings is replaced with other heterocycles such as thiophene, furan, etc., are very few. , Lash and co-workers reported the first synthesis of nonaromatic heterobenziporphyrins in which one of the pyrrole rings was replaced either by thiophene Ia or furan Ib (Chart ).…”

A “click-chemistry” approach for the synthesis of porphyrin dyads as sensitizers for dye-sensitized solar cells

“…60,62,63 Cu-catalyzed Huisgen 1,3-dipolar cycloaddition between azide-and acetylene-containing derivatives is the most effective reaction of this type which has led to a variety of porphyrin, phthalocyanine and other chromophore containing systems. [64][65][66][67][68][69][70] The 1,2,3-triazole bridge that results from such reactions has been proven to be very efficient for energy transfer in donor-acceptor systems. 71,72 Also, according to literature reports, the measured efficiencies for a variety of mono-carboxylphenyl triaryl porphyrins have shown values from 0.5 to 3% in standard DSSCs.…”

Synthesis and specific fluoride binding properties of expanded dithiacalixphyrins

“…may lead to core-modified calixphyrins which may exhibit interesting electronic and structural features that differ from calixphyrins. 17,18 A few years back, we reported thiacalixphyrins 19,20 1 and 2 (Chart 1) containing one or two thiophene sulfur(s) in place of pyrrole nitrogen(s) and showed that the thiacalixphyrin properties were quite novel and different from those of thiaporphyrins. In thiacalixphyrins 1 and 2, the thiophene(s) and pyrroles were connected by one sp 3 -and three sp 2 meso-carbon bridges (Chart 1).…”