An Examination of the Steric and Electronic Effects in the Copolymerization of Carbonyl Sulfide and Styrene Oxide

摘要: The completely alternating copolymerization of carbonyl sulfide (COS) and styrene oxide was found to occur under mild reaction conditions (0–30 °C 1.5 MPa) in the presence (salen)CrCl/onium salt catalyst systems afford high molecular weight poly(monothiocarbonates) with narrow distributions. Ring-opening shown be 88% selective at methylene carbon. That is driven by steric hindrance, where ring-opening occurs preferentially less congested carbon center. Similar results were upon utilizing tetramethyltetraazaannulene (tmtaa)CrCl/onium catalyst. On other hand, employing a zinc–cobalt double metal cyanide (Zn–Co DMCC) catalyst, ligands around active zinc site are not sterically encumbering, predominantly methine site; i.e., electronically driven.