Phosphasalen Yttrium Complexes: Highly Active and Stereoselective Initiators for Lactide Polymerization

Abstract : Preparation and characterization of three yttrium alkoxide complexes with new phosphasalen ligands are reported. The phosphasalens are analogues of the well-known salen ligands but with iminophosphorane donors replacing the imine function- ality. The three yttrium alkoxide complexes show mono- and dinuclear structures in the solid state, depending on the substituents on the ligand. The new ligands and complexes are characterized using multinuclear NMR spectr oscopy, mass spectrometry, elemental analysis, and single-crystal X-ray diffraction experiments. The complexes are all rapid initiators for lactide polymerization; they show excellent polymerization control on addition of exogeneous alcohol. The mononuclear complex shows extremely rapid rates and a high degree of stereocontrol in rac-lactide polymerization, yielding heterotactic PLA (Psof 0.9). The phosphasalens are, therefore, excellent ligands for lactide ring-opening polymerization catalysis showing superior rates and stereocontrol versus salen ligands, which may be related to their excellent donating ability and the high degrees of steric protection they can confer.
Document type :
Journal articles
Complete list of metadatas

https://hal-polytechnique.archives-ouvertes.fr/hal-00904993
Contributor : Francoise Girard <>
Submitted on : Friday, November 15, 2013 - 4:27:17 PM
Last modification on : Tuesday, July 30, 2019 - 8:26:01 AM

Identifiers

Collections

Citation

Thi-Phuong-Anh Cao, Antoine Buchard, X. Le Goff, Audrey Auffrant, Charlotte K. Williams. Phosphasalen Yttrium Complexes: Highly Active and Stereoselective Initiators for Lactide Polymerization. Inorganic Chemistry, American Chemical Society, 2012, 51, pp.2157-2169. ⟨10.1021/ic202015z⟩. ⟨hal-00904993⟩

Share

Metrics

Record views

221