Synthesis of linear and branched poly(phenylacetylene)s through Mizoroki-Heck coupling reaction of vinyl bromides

Polyacetylene and its derivatives are a class of traditional conjugated polymers that started the era of conducting plastics. In this paper, we develop a new approach of synthesizing substituted poly(phenylacetylene)s through Mizoroki-Heck coupling of vinyl bromides. A series of & alpha;-bromostyrene derivatives are synthesized and used as the monomers for the polycoupling reaction. It is found that K2CO3 is the effective base while Et3N shows almost no catalytic reactivity. Gel permeation chromatography (GPC) results indicate that the molecular weight distribution is broad, which is typical for step growth polymerization. A kinetic study shows that electron withdrawing group on the phenyl ring increase the polymerization rate of the corresponding monomer. Furthermore, incorporating both aryl and vinyl halides into a single vinyl monomer allows the synthesis of branched polyacetylene possessing oligo(phenylene vinylene) at the branch points. The current approach may serve as a new tool for the molecular engineering of substituted polyacetylene materials.

Automated summary

In this study, substituted poly(phenylacetylene)s were synthesized through Mizoroki-Heck coupling reaction using α-bromostyrene derivatives as monomers. K2CO3 was found to be an effective base, while Et3N showed little catalytic reactivity. Kinetic study showed that electron withdrawing group on the phenyl ring increased the polymerization rate of the corresponding monomer. Additionally, incorporating aryl and vinyl halides into a single vinyl monomer allowed the synthesis of branched polyacetylene with oligo(phenylene vinylene) at the branch points. This approach provides a new tool for the molecular engineering of substituted polyacetylene materials.