2,5-substituted PPV-derivatives with different polarities: The effect of side chain polarity on solubility, optical and electronic properties

Three 25-substituted polar PPV derivatives have been prepared using the sulfinyl precursor route and compared to the apolar MDMO-PPV. All polymers were obtained in excellent yield and with improved purity as compared to other methods. The influence of the polarity of the side chains, i.e. oligo(oxyethylene) and alkyl substituents, on the optical and electronic properties were investigated. In thin films, the oligo(oxyethylene) substituents do not significantly alter the optical properties of the conjugated backbone and the field effect mobility. In contrast, other thin film electrical properties, such as relative permittivity and conductivity, are markedly affected by the polar substituents. This is also the case for their solubility and solution properties. The polar PPV-derivatives are not only soluble in a wide range of solvents, but also exhibit aggregation phenomena.