Brightly full-color emissions of oligo(p-phenylenevinylene)s: substituent effects on photophysical properties

A simple and effective strategy for synthesis of bis-dipolar trimeric OPVs (a–g) with same push–pull electron groups at the two ends is presented. Their photophysical and electrochemical properties were investigated by UV–vis, fluorescence spectroscopies, and voltammetry techniques. A successful tuning in the emission color was achieved and the LUMO energy level was found to correlate with the Hammett constant of the respective substituents, providing a powerful strategy for prediction of the photoelectrical properties of the new chromophores.