Synergy effect of aluminum complexes during the ring-opening polymerization of ε-caprolactone: Inductive effects between dinuclear metal catalysts

Synthesis of Mono- and Dinuclear Aluminum Complexes Bearing Aromatic Amino-Phenolato Ligands: A Comparative Study in the Ring-Opening Polymerization of Cyclohexene Oxide

“…In addition, the catalytic activity of 5 with longer Al–Al distances was better than that of 4 (8.137 Å for 4 and 9.401 Å for 5 ). The change of polymerization activity caused by modification in the linkers was also observed in some bimetallic complexes, possibly because aromatic diamine linkers not only affect the distances between the two Al centers, but may also change the Lewis acidity of the aluminum centers to regulate the polymerization reaction. Additionally, the PDI of the resulting polymers gradually broadened ( Đ = 2.36–3.04), indicating that the polymerization became less controlled with increasing Al–Al distances.…”