Multi-role heterogeneous Zn–Co double metal cyanide catalysts valid for ring-opening polymerizations and hydrofunctionalizations

Abstract

Double metal cyanides (DMCs) or Prussian blue analogs are well-known solid complexes, especially because of their gas and energy storage ability and catalytic activity for epoxide polymerization. The crystal structure, as well as the electron-donating complexing agent, has a crucial effect on the catalytic activity and selectivity of these materials. In this study, we developed a feasible process for fabricating Zn–Co DMC catalysts, which have a range of crystal structures, using organosilicon complexing agents. In addition, the transformation of the complexing agent during catalyst preparation was investigated using density functional theory calculations to understand the nature of the active sites. The resultant catalysts exhibited excellent activities, good selectivities, as well as a broad substrate scope, for the homopolymerization of epoxide and lactone (turnover frequency up to 564 min−1), copolymerization of epoxide with CO2 (up to 99 % yield), and hydrofunctionalization reactions of terminal alkynes (up to 95 % yield), which are among the most important applications of DMC catalysis.