Star-shaped perylene-oligothiophene-triphenylamine hybrid systems for photovoltaic applications

A series of novel star-shaped donor-acceptor systems is described. These molecules consist of three head-to-tail coupled oligo(3-hexylthiophene) arms covalently linked to a triphenylamine core which acts as the donor part. At the termini perylene monoimide moieties are attached as acceptors. These hybrid molecules, which differ by the length of the oligothiophene units, were effectively synthesized via palladium-catalyzed Suzuki-type couplings. Their optical and electrochemical properties were determined and structure-property relationships were established, clearly demonstrating the influence of the length of the integrated oligothiophene chains on the electronic nature of these hybrid systems.