Methoxyaryl substituted aluminum ketiminate complexes and its activity in ring opening polymerization processes

Abstract

The synthesis of dimethyl aluminum (LoAlMe2) and chloromethyl aluminum (LoAlMeCl) complexes containing ketiminate ligand [(2-MeO)C6H4]N(H)C(Me)=CHC(Me)=O (LoH) is reported along with the preparation of Lo3Al from LoH and LiAlH4, and ionic [Lo′Al(thf)3]I from LoAlMe2 and I2. In the later complex the pseudooctahedral geometry of the aluminum ion by terdentate ligand {[(2-O)C6H4]NC(Me)=CHC(Me)=O}2− (Lo′), originated from Lo ligand by the methyl group abstraction, and three THF molecules are observed. Structures of these complexes were determined by X-ray techniques. The activity of LoAlMe2 and LoAlMeCl as initiators of ring opening polymerization of ε-caprolactone, trimethylene carbonate and l-lactide, and (co)polymerization of cyclohexene oxide and carbon dioxide was studied.