Effect of the mode of fixation of the thienyl rings on the electronic properties of electron acceptors based on indacenodithiophene (IDT)

Abstract

Indacenodithiophene (IDT) is a major building block for the design of advanced functional π-conjugated polymers and nonfullerene electron-acceptor materials for organic photovoltaics. Preliminary results of a synthetic approach aiming at the modulation of the electronic properties of IDT-based acceptors by modification of the mode of linkage of the thiophene rings with the median phenyl ring are presented. The synthesis of three acceptor-donor-acceptor (A-D-A) structures corresponding to the different possible modes of thiophene-phenyl connection (1–3) is described and their electronic properties are discussed on the basis of the results of UV–Vis absorption spectroscopy, cyclic voltammetry and theoretical calculations.