Synthesis of push–pull triarylamine dyes containing 5,6-difluoro-2,1,3-benzothiadiazole units by direct arylation and their evaluation as active material for organic photovoltaics

Two push–pull molecules involving a triarylamine donor unit connected to a dicyanovinyl acceptor moiety by a difluorobenzothiadiazole-thienyl block have been synthesized. In order to simplify the synthesis, avoid intermediate halogenation reactions and the formation of toxic organometallic by-products, building blocks were connected by direct (hetero)-arylation. The optimization of the experimental conditions of the coupling reactions is thus reported herein as well as the preliminary evaluation of the potential of the target compounds as active material in simple air-processed organic solar cells.