Ring-opening polymerization and copolymerization of cyclic esters catalyzed by amidinate aluminum complexes

A series of new alkyl mono- and bimetallic aluminum complexes supported by novel amidinate ligands has been prepared in very high yields. These complexes were fully characterized by spectroscopic methods. Alkyl aluminum complexes 1–6 were investigated as catalysts for the ring-opening polymerization and copolymerization of e-caprolactone and L-lactide. Under the optimal reaction conditions, complex 5 acts as an efficient single-component initiator for the ring-opening polymerization and copolymerization of cyclic esters to yield biodegradable polyester materials with narrow polydispersities. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2397–2407