om7b00068_si_001.pdf (1.37 MB)
Download fileImprovement in Aluminum Complexes Bearing Schiff Bases in Ring-Opening Polymerization of ε‑Caprolactone: A Five-Membered-Ring System
journal contribution
posted on 2017-05-08, 11:49 authored by Chieh-Ling Lee, Ya-Fan Lin, Man-Ting Jiang, Wei-Yi Lu, Jaya Kishore Vandavasi, Li-Fang Wang, Yi-Chun Lai, Michael Y. Chiang, Hsuan-Ying ChenA series
of five- and six-membered-ring Al complexes bearing Schiff
bases was synthesized and their application to the ring-opening polymerization
of ε-caprolactone (CL) was studied. The five-membered-ring Al
complexes have been shown to have a significantly higher polymerization
rate than six-membered-ring Al complexes (2–3 fold for CL polymerization).
The X-ray data revealed that the Al center of a five-membered-ring
Al complex is farther from the Schiff base ligand than is that of
a six-membered-ring Al complex. The results of density functional
theory calculations also suggest that more space around the Al center
of five-membered-ring Al complexes may reduce the steric repulsion
in CL polymerization and increase the catalytic activity of five-membered-ring
Al complexes.