Polycarbonates made using high activity catalysts

摘要

Polycarbonates having Mn ranging from about 5,000 to about 40,000 and a molecular weight distribution ranging from 1.05 to 2.0 are prepared from epoxides and CO2 using a catalyst which has a Zn center and two ligands where one of the ligands is a propagating group and the other of the ligands is not a propagating group and an activity of at least one turnover per hour, preferably at least 100 turnovers per hour. Preferred catalysts have a moiety with group on each nitrogen containing a phenyl moiety.