Polynuclear and Halogenated Structures in Polyphenylenes Synthesized from Benzene, Biphenyl, and p-Terphenyl under Various Conditions: Characterization by Laser Desorption/Fourier Transform Mass Spectroscopy
Journal of Polymer Science: Part A, Polymer Chemistry
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.