Polynuclear and halogenated structures in polyphenylenes synthesized from benzene, biphenyl, and <i>p</i>‐terphenyl under various conditions: Characterization by laser desorption/fourier transform mass spectrometry

Abstract

Abstract Polyphenylenes made by reaction of benzene, biphenyl, or p ‐terphenyl with metal halide catalyst–oxidant systems are complex mixtures of dissimilar oligomers, which include halogenated and polynuclear structures, according to positive and negative‐ion laser desorption/Fourier transform mass‐spectral analyses. Polymerization of benzene with metal‐chloride salts that terminate chain elongation by chlorination of the end rings appears to decrease formation of polynuclear structures by providing a competing pathway for chain termination. Polynuclear structures occur to a greater extent with oligomerization of biphenyl than with benzene, presumably because of isomerization and increased opportunity for π overlap during propagation. Electrical conductivities of polyphenylenes made by various routes should not be discussed solely in terms of the linear poly( p ‐phenylene) structure.