Synthesis and Ring-Opening Polymerization of Antimony(III)-Bridged [1]Ferrocenophanes

Main-group-bridged [1]ferrocenophanes enable the incorporation of a variety of elements into polyferrocene materials through ring-opening polymerization. While antimony-containing materials have been used as flame retardants and photolithographic resists, there exists only a single example of a Sb(III) main-chain polymer. We have used the ring-opening of a stiba[1]ferrocenophane as a facile route to expand the family of Sb(III) main-chain polymers. Two examples of stiba[1]ferrocenophanes were synthesized and characterized, featuring bulky mesityl and terphenyl substituents at antimony, fc(SbMes) and fc(SbTer). fc(SbTer) was found to undergo thermal ring-opening polymerization to form a soluble and robust polymeric material, PFSbTer. These results further expand the range of polyferrocenes and provide access to a new class of Sb(III)-containing materials.