Construction of Hyperbranched Polyphenylenes Containing Ferrocenyl Units by Alkyne Polycyclotrimerization

Copolycyclotrimerizations of [(<i>E</i>/<i>Z</i>)-2-(1-ferrocenyl)vinyl]-<i>m</i>/<i>p</i>-phenylacetylene [(<i>E</i>/<i>Z</i>)-<b>1</b>(<i>m</i>/<i>p</i>)] with 1,8-nonadiyne (<b>I</b>) were studied. The conformation of the vinyl unit of <b>1</b> affected the polycyclotrimerization reaction dramatically:  while (<i>Z</i>)-<b>1</b> failed to give any polymeric products, its <i>E</i> isomer underwent polymerization smoothly, producing hyperbranched copolymers <i>hb-</i>P<b>1</b>/<b>I</b> 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.