Highly regioselective and alternating copolymerization of carbonyl sulfide with phenyl glycidyl ether

Polymer structures containing sulfur atoms can provide enhancement of important polymer properties compared to their oxygen-containing counterparts. In this regard, the copolymerization of phenyl glycidyl ether and carbonyl sulfide has been very effectively achieved employing (salen)CrCl in the presence of an onium salt at ambient temperature. The resulting copolymer is shown to be completely alternating and to possess extremely high regioselectivity in the epoxide ring-opening step. That is, the ring-opening step predominantly occurs at the less sterically hindered methylene carbon–oxygen bond leading to a tail-to-head structure (98%) in the copolymer. This observation was further confirmed when using the chiral epoxide monomer, (S)-PGE.