Aluminum Complexes of Monopyrrolidine Ligands for the Controlled Ring-Opening Polymerization of Lactide

作者:Beament James; Mahon Mary F; Buchard Antoine*; Jones Matthew D*
来源:Organometallics, 2018, 37(11): 1719-1724.
DOI:10.1021/acs.organomet.8b00161

摘要

In this paper we report the full characterization (solution-state NMR spectroscopy and solid-state structures) of a series of Al(III) half-salan complexes and their exploitation for the ring-opening polymerization of rac-lactide. Depending on the ligand employed and stoichiometry of the complexation, structures of the form Al(X)(2)Me or Al(X)Me-2 were isolated. Interestingly Al(2)(2)Me and Al(2)Me-2 produce PLA with a strong isotactic bias (P-m up to 0.80), whereas all other complexes produced atactic PLA. This is in contrast to recent studies on similar salan ligand systems. PLAs with predictable molecular weights and narrow distributions were achieved. The results are discussed in terms of steric and electronic properties of the ligands.

  • 出版日期2018-6-11