‘Radical-controlled’ oxidative polymerization of o-cresol catalyzed by μ-η2 : η2-peroxo dicopper(II) complex Original Research Article

Described is an oxidative polymerization of o-cresol catalyzed by (1,4,7-triisopropyl-1,4,7-triazacyclononane)copper complex, from which a μ-η2 : η2-peroxo dicopper(II) complex is formed under dioxygen. This complex reacts with o-cresol to give ‘controlled’ phenoxy radical-copper(I) complex exclusively without formation of ‘free’ phenoxy radicals. The resulting polymer was composed mainly of 2-methyl-1,4-phenylene oxide unit and showed high thermal stability. The polymerization catalyzed by (N,N,N′,N′-tetramethylethylenediamine)copper complex, a typical catalyst for 2,6-dimethylphenol polymerization, gave the polymer containing larger amounts of o-linkage structures and quinone moieties.