Novel thieno[3,4-c]pyrrole-4,6-dione-based conjugated copolymers with donor-acceptor structures

A series of novel copolymers with alkylthiophene/alkoxythiophene and the thieno[3,4-c]pyrrole-4,6-dione moieties were synthesized by Sonogashira cross-coupling reactions. The structures and properties of these copolymers were characterized using FT-IR, (1)H NMR, UV-Vis, thermal gravimetric analysis, different scanning calorimetry, and cyclic voltammetry (CV). All of the copolymers possess adequate thermal stability, and exhibit good solubility in common organic solvents such as THF, chloroform, and toluene. The electrochemical and photophysical properties were investigated, and the results show that the spectral response of these copolymers are extended up to 700, 750, and 640 nm for P (1) , P (2) , and P (3) , respectively. CV studies reveal that the band gaps of these copolymers range from 1.51 to 1.97 eV, implying that the resulted polymers may be promising candidates for solar cells.