Catalytic Polymerizations of Hydrophobic, Substituted, Acetylene Monomers in an Aqueous Medium by Using a Monomer/Hydroxypropyl-β-cyclodextrin Inclusion Complex

Ten hydrophobic, substituted, acetylene monomers were examined as to their abilities to form an inclusion complex with hydroxypropyl-beta-cyclodextrin (HPCD). Only the monomers with suitable substitutents were found to form the monomer/HPCD complex, which was identified by NMR, FTIR, and UV-vis spectroscopy. Polymerizations of the monomers were successfully carried out in aqueous solution by using the prepared monomer/HPCD inclusion complex and by using a water-soluble Rh-based catalyst, [Rh(cod)(2)BF4] or [Rh(nbd)(H2O)OTs]. Such polymerizations provided high-yield (> 90%) polymers with a cis content of approximately 100%. The as-prepared polymers could take an ordered helical conformation, just like their counterparts obtained in organic solvents.