Toward sustainable organic semiconductors from a broad palette of green reactions

New conjugated materials, based on TPA-thiophene moieties and integrating azomethine bonds with dibenzofuran unit or cyanovinyl bond with phenyl-thiophene and bithiophene units, have been synthesized by using a wide range of green reactions such as direct heteroarylation coupling reaction, Knoevenagel and Schiff base condensations and Stille cross coupling reaction from thiophene-containing organotin reagent supported on ionic liquid. The electronic properties of the new molecules were analyzed by using UV/Vis spectroscopy and cyclic voltammetry. The potential use of the molecules as donor materials for photovoltaic conversion were evaluated in simple bilayer solar cells by using C60 fullerene as acceptor material, leading to performances reaching up 2% of PCE.