Synthesis, spectroscopy and electrochemistry study on a novel di-silyl substituted poly(p-phenylenevinylene)

A novel di-silyl substituted poly(p-phenylenevinylene) (PPV) derivative is synthesized through the Gilch route. The polymer is solution processable and shows high thermal stability in air. UV-Vis spectra for the film and solution samples illustrate some different features, in which the absorption peak corresponding to the π-π^* transition of the delocalized electrons along the polymer back bone is red shifted and broadened in the film state compared to the solution one. The fluorescent emission spectra are quite similar for the polymer in solution and in the solid states. Cyclic voltammetric investigation reveals a partially reversible n-doping process and an irreversible p-doping process. The cathodic current is much greater than that of the anodic one, which means the polymer has the tendency to be charged through n-doping rather than p-doping process. The improved affinity of the polymer to electrons may be owing to the low interface barrier between the polymer films and the electrode surface. The HOMO and LUMO energy levels have also been estimated from the data of oxidation and reduction onset potentials. All of the results indicate that the synthesized polymer is a promising green emissive material for the light-emitting device application.