Group 4 salalen complexes and their application for the ring-opening polymerization of rac-lactide

Emma L Whitelaw, Matthew D Jones, Mary F Mahon

Research output: Contribution to journalArticle

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Abstract

In this paper, we report the preparation and characterization of a series of unsymmetrical group 4 metal complexes based on ONNO salalen-type ligands. In these examples, the ligand is unsymmetrical with an amine and an imine nitrogen center. All complexes {except Hf(3)(OiPr)2} adopt a β-cis configuration in the solid state, which is also in agreement with solution-state NMR spectroscopic measurements. The complexes have been tested for the ROP of rac-lactide (both in solution and under melt conditions). Narrow polydispersities have been seen (1.07−1.82). The Ti(IV) complexes produce atactic PLA, whereas the Zr(IV) complexes form PLA with a heterotactic bias. Hf(IV) complexes have been shown to produce isotactic PLA with a Pm of 0.75. The kinetics for all initiators have been investigated and are discussed.
Original languageEnglish
Pages (from-to)7176-7181
Number of pages6
JournalInorganic Chemistry
Volume49
Issue number15
Early online date1 Jul 2010
DOIs
Publication statusPublished - 2 Aug 2010

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Ring opening polymerization
polymerization
Ligands
ligands
Imines
rings
Coordination Complexes
Polydispersity
initiators
imines
Amines
amines
Nitrogen
Nuclear magnetic resonance
solid state
nitrogen
preparation
nuclear magnetic resonance
Kinetics
kinetics

Cite this

Group 4 salalen complexes and their application for the ring-opening polymerization of rac-lactide. / Whitelaw, Emma L; Jones, Matthew D; Mahon, Mary F.

In: Inorganic Chemistry, Vol. 49, No. 15, 02.08.2010, p. 7176-7181.

Research output: Contribution to journalArticle

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