Soluble Bimetallic Oxoalkoxide Catalysts. IV. Ring-Opening Polymerization of β-Propiolactone

The polymerization of β-propiolactone by aluminum-zinc oxoalkoxides corresponding to the structure has been studied. The overall kinetics of the reaction follow a first current order in monomer and a first order in catalyst. Mechanistic studies also indicate that these initiators operate through selective acyl-oxygen cleavage of the lactone ring with insertion in the aluminum-oxygen bond. Moreover, the polymerization proceeds by a perfectly “living” process.