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 degrees C). The incorporation of the ferrocenyl moiety endowed the copolymers with redox activity.