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

abstract

  • 2015 American Chemical Society. The completely alternating copolymerization of carbonyl sulfide (COS) and styrene oxide was found to occur under mild reaction conditions (0-30 C and 1.5 MPa) in the presence of (salen)CrCl/onium salt catalyst systems to afford high molecular weight poly(monothiocarbonates) with narrow molecular weight distributions. Ring-opening of styrene oxide was shown to be 88% selective at the methylene carbon. That is the reaction is driven by steric hindrance, where ring-opening occurs preferentially at the less congested carbon center. Similar results were found upon utilizing the tetramethyltetraazaannulene (tmtaa)CrCl/onium salt catalyst. On the other hand, upon employing a zinc-cobalt double metal cyanide (Zn-Co DMCC) catalyst, where the ligands around the active zinc site are not sterically encumbering, ring-opening of styrene oxide occurs predominantly at the methine carbon site; i.e., the reaction is electronically driven.

published proceedings

  • MACROMOLECULES

author list (cited authors)

  • Luo, M., Zhang, X., & Darensbourg, D. J.

citation count

  • 44

complete list of authors

  • Luo, Ming||Zhang, Xing-Hong||Darensbourg, Donald J

publication date

  • September 2015