RING-OPENING POLYMERIZATIONS OF LACTONE AND EPOXIDE INITIATED WITH ALUMINUM COMPLEXES OF SUBSTITUTED TETRAPHENYLPORPHYRINS - MOLECULAR DESIGN OF HIGHLY-ACTIVE INITIATORS

Ring-opening polymerization of β-propiolactone with a series of aluminum complexes of substituted tetraphenylporphyrins gave polymer with narrow molecular weight distribution, where the aluminum porphyrins (tetrakis(2',4',6'-trimethoxyphenyl)porphinato)aluminum chloride, (tetrakis(2',6'-dimethoxyphenyl)porphinato)aluminum chloride, and (tetrakis(2',6'-dichlorophenyl)porphinato)aluminum chloride were much more active than nonsubstituted (tetraphenylporphinato)aluminum chloride. These aluminum ortho-disubstituted tetraphenylporphyrins were also active as initiators for the polymerizations of δ-valerolactone and 1,2-epoxypropane both in the absence and presence (immortal polymerization) of methanol as a protic chain-transfer agent. © 1990, American Chemical Society. All rights reserved.