Luminescence properties of end-substituted oligo(phenylenevinylene)s

We have used three soluble three-phenyl-ring oligo(phenylenevinylene)s (OPV(1)s) with poly(alkyleneoxy) electron donors and hexylsulfonyl electron acceptors to investigate the end-substitution effect. Besides the increase in solubility, the end substitution is found effective in fine tuning the absorption and emission properties. Symmetrically substituted OPV(1)s, with the same donor or acceptor end-groups, show a small red shift in their absorption and emission spectra as compared to the unsubstituted OPV(1). Asymmetrically substituted OPV(1), with a donor at one end and an acceptor at the other, shows a larger red shift in both the absorption and emission spectra due to the increased π-electron delocalization associated with the “push–pull” effect of the donor and acceptor in the molecule.