Multifunctional properties of monodisperse end-functionalized oligophenylenevinylenes
Novel series of monodisperse, end-functionalized oligophenylenevinylenes (OPVs) containing up to eight phenyl rings have been designed and synthesized by a convergent approach using the stereoselective Wadsworth–Emmons reactions for an investigation of technologically useful functional properties. According to PM3 semiempirical quantum mechanical calculations, the frontier molecular orbitals and the energy gap of an OPV could be shifted or tuned by the functional substituent(s) that are incorporated as end-caps. Our theoretical and experimental evidences have shown that the end-substituents of an oligomer do not affect coplanarity of the pi-conjugated system. It has also been found that the newly synthesized OPVs can exhibit various useful functional properties such as light-emitting properties, photovoltaic effects, third-order nonlinear optical responses, and chemical sensing properties depending on the nature of the end-substituents. In this contribution, the structural factor(s) that can enhance a specific functional property of a molecule or material will be discussed.