Preparation and properties of poly(p-phenylene) and its ring-substituted derivatives

Summary form only given. Poly(p-phenylene) (PPP) is thermally stable and moderately conducting and its properties are largely improved by introducing suitable substituents on phenyl nuclei. Although PPP was first prepared in 1936, it has become increasingly important to determine route to high quality PPP polymers. We prepared PPP by dehalogenative coupling of benzene rings with zerovalent nickel generated in situ, which allowed us to prepare derivatives of PPP bearing functional groups like keto group, carboxylic ester, suffonic ester and alkyl group. These derivatives were soluble in organic solvents and showed interesting properties.