A DFT study of the effects of donor-to-acceptor ratio on the electronic properties of copolymers based on tricyclic non-classical thiophene

作者：Fu, Yangwu^*; Wang, Haibao; Chen, Mingjun; Shen, Wei

来源：Molecular Simulation, 2011, 37(6): 478-487.

DOI：10.1080/08927022.2011.554547

• density functional theory
• [1,2,5]thiadiazolo[3,4-b]thieno-[3,4-e]pyrazine
• ratio of donor-to-acceptor
• electronic properties
• thienothiophene

The geometries and electronic properties of the 1D polymers composed of thieno[3,2-b] thiophene (TT), thiophene (T), pyrrole (P), furan (F) and tricyclic non-classical thiophenes ([1,2,5]thiadiazolo[3,4-b]thieno-[3,4-e]pyrazine, TTP) are investigated systematically by the density functional theory method at the B3LYP level with 6-31G(d) basis set. The theoretical study suggests that the ratio of donor-to-acceptor (D-A ratio) plays a crucial role in the geometric and electronic properties for the alternating donor-acceptor polymers. The increase in the D-A ratio leads to an increase in the bridge bond length and an inverse change in the bond-length alternation. Furthermore, the increase in the portion of donor units can lead to an obvious reduction in band gap for these studied polymers. The TT-containing polymer possessing the D-A ratio of 2: 1 (p-BTTTTP) that is predicted to have a small band gap of 0.25 eV and a relatively small effective mass of carriers is a good candidate for an intrinsic conducting polymer. Therefore, the tricyclic non-classical thiophenes (TTP) and TT are good building blocks that can lead to small band gap polymers.

• 出版日期2011
• 单位重庆三峡学院; 西南大学