Construction of hyperbranched polyphenylenes containing ferrocenyl units by alkyne polycyclotrimerization

Copolycyclotrimerizations of [(E/Z)-2-(1-ferrocenyl)vinyl]-m/p- phenylacetylene [(E/Z)-1(m/p)] with 1,8-nonadiyne (I) were studied. The conformation of the vinyl unit of 1 affected the polycyclotrimerization reaction dramatically: while (Z)-1 failed to give any polymeric products, its E isomer underwent polymerization smoothly, producing hyperbranched copolymers hb-P1/I in good to high yields (up to 100 wt %). The hyperbranched copolymers are soluble in common organic solvents and are thermally stable, losing little of their weights when heated to high temperatures (up to 466°C). The incorporation of the ferrocenyl moiety endowed the copolymers with redox activity.