Dithienylbenzodipyrrolidone: New Acceptor for Donor–Acceptor Low Band Gap Polymers

An
analogue of DPP, dithienylbenzodipyrrolidone (DTBDPD), was successfully
synthesized. Several D–A copolymers, with different electron
donating capability donor unit (fluorene, difluorene, dithienosilole,
and dithienopyrrole) and DTBDPD acceptor, were prepared by means of
Suzuki and Stille coupling reaction. The optical and electrochemical
properties were demonstrated through UV–vis–NIR absorption
and cyclic voltammetry (CV). All polymers showed near-infrared or
even infrared absorption and deeper LUMO levels, as low as −3.80
eV.