Syntheses of novel copolymers containing carbazole and their electrochromic properties

► 2,5-Bis(3,6-di(thiophen-3-yl)-9H-carbazol-9-yl)thiophene were synthesized via Ullmann and Suzuki couplings. ► 1,4-Bis[(3,6-di(thiophen-3-yl)-9H-carbazol-9-yl)methyl]benzene were synthesized via Ullmann and Suzuki couplings. ► Copolymers with thiophene, 3,4-ethylenedioxythiophene and pyrrole were synthesized by electrochemical polymerization. ► Electrochromic properties of the compounds were investigated. ► Structural characterizations were performed by FT-IR and X-ray Photoelectron Spectroscopy.