Synthesis and band gap determination for 4-phenyl-7-(5-(thiazol-2-yl) thien-2-yl)benzo[c][1,2,5]thiadiazole, a new polyheterocyclic molecule with potential applications as a semiconductor in organic photovoltaic solar cells

Abstract

Organic photovoltaic (OPV) solar cells are a promising emerging technology for sustainable energy generation. In these cells, the absorbing layer consists of a repeated series of aromatic organic rings with a system of π delocalized electrons, a feature that allows these materials to absorb sunlight and facilitate electron transfer. In the present work, a new tetrameric molecule with high structural complexity, 4-phenyl-7-(5-(thiazol-2-yl) thien-2-yl)benzo[c][1,2,5]thiadiazole, was synthesized by a convergent pathway. The final step of the synthetic route was the Suzuki coupling of two new dimeric molecules, obtained from commercially available raw materials such as thiophene and o-phenylenediamine. The band gap of the final compound was found to be 2.5 eV using an optical methodology and 2.38 eV using an electrochemical methodology. The results suggest that this tetrameric molecule has potential for application in OPV cells.