In situ optical and magnetic measurements in substituted poly( p-phenylene vinylene)

Abstract

The electrochemical, optical and magnetic properties in poly( p-phenylene vinylene) and its derivatives such as poly(2,5-dimethoxy- p-phenylene vinylene), poly(2,5-diethoxy- p-phenylene vinylene), poly(1,4-naphthalene vinylene) poly(thiophene vinylene) etc. during electrochemical p-type doping have been investigated by cyclic voltammetry, optical absorption spectrum and electron spin resonance measurements. The evolution of localized states is evidenced by the spectral change with electrochemical doping. Oxidation potential and localized states have changed markedly by the substitution and also by introduction of naphthalene and thiophene rings inside of phenylene rings. Evolution of localized state upon doping is also dependent on molecular structure. Especially, in poly(1,4-naphthalene vinylene) successful n-type doping is expected. These results are discussed in terms of polaron and/or bi-polaron model.