Synthesis and Characterization of Dinuclear Aluminum Complexes Bearing N,N-Dialkylaniline-amido Ligands and Its Catalytic Properties for Lactone Polymerization

Two ligands[ortho-C₆H₄NR₂(CH₂NH)]₂CH₂CH₂(3: R=Me; 4: R=Et) were prepared by the reduction of preligands[ortho-C₆H₄NR₂(CH=N)]₂CH₂CH₂(1: R=Me; 2: R=Et). These ligands reacted with AlMe₃ to afford the corresponding dinuclear aluminum complexes {AlMe₂[ortho-C₆H₄NR₂(CH₂N)]}₂CH₂CH₂(5: R=Me; 6: R=Et). All the compounds were characterized by ¹H and ¹³C nuclear magnetic resonance(NMR) spectroscopies and elemental analyses. The catalytic properties of the aluminum complexes towards the ring-opening polymerization of lactones were investigated in the presence of benzyl alcohol. All the polymerization reactions were proceeded in a controlled manner.