A computational study on 4,7-di(furan-2-yl)benzo[c][1,2,5] thiadiazole monomer and its oligomers

Abstract

The energy gap, Eg, between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molec ular orbital (LUMO) energy levels that determines the elec tronic and optical properties of 4,7-di(furan-2- yl)benzo[c][1,2,5]thiadiazole (FSF) polymer is calculated by performing quantum chemical calculations. First, we theoret ically investigated the most stable conformers of FSF mono mer and its corresponding oligomers at the B3LYP/6-31G(d) and B3LYP/LANL2DZ levels of theory. We reveal the theoret ical molecular structure of this very recently synthesized novel monomer and its oligomers for the first time in the literature. Our results from the B3LYP/6-31G(d) calculations indicated that FSF polymer has a low HOMO-LUMO gap of 1.55 eV to be in good agreement with the experiments. Experimental design and synthesis of novel conjugated polymers require time-consuming and expensive procedures. The findings from this study are promising for the use of computational methods in the design of the novel conjugated polymers, and help to narrow the materials to be used in design and synthesis of conjugated polymers with desired properties.