Palladium Catalyzed Phenylacetylene Polymerization to Low Molecular Weight cis-Transoidal and trans-Cisoidal Poly(phenylacetylene)s: A Perspective

This is a short perspective on palladium catalyzed polymerization of phenylacetylene that lead to much lower molecular weight poly(phenylacetylene)s (Mw 3 000-60 000 Da) in contrast to polymers made from rhodium and iridium catalyzed reactions (Mw >100 000 Da). It looks at the effects of ligands on both polymer molecular weight and microstructure and compares these two properties with polymers obtained from other catalysts for both early and late transition metals. It is clear from this review that palladium produces mainly mixtures of low molecular weight cis-transoidal and trans-cisoidal poly(phenylacetylene)s and that in order to selectively make a specific microstructure of poly(phenylacetylene) of high molecular weight, the current catalysts design for palladium has to change.