Tuning the thiolen: Al(III) and Fe(III) thiolen complexes for the isoselective ROP of rac-lactide

Jack Stewart, Paul McKeown, Oliver Driscoll, Mary Mahon, Benjamin Ward, Matthew Jones

Research output: Contribution to journalArticle

5 Citations (Scopus)
4 Downloads (Pure)

Abstract

A series of five iron and aluminum complexes bearing {ONSO} imine thiobis(phenolate) ligands have been prepared and applied to the ring-opening polymerization (ROP) of rac-lactide. Fe(1)Cl produced polylactide with a very strong isotactic bias (P m = 0.79-0.89) and well-defined melting temperatures (T m = 154-181 °C). The polymers have been characterized by a combination of 1H{ 1H} NMR, 13C{ 1H} NMR, gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, and powder X-ray diffraction. Fe(1)Cl has also been shown to activate CO 2, at atmospheric pressure and concentrations, to form a carbonato-bridged dimer. Fe(2-5)Cl and Al(1-5)Me were also active for lactide ROP demonstrating good-molecular-weight control (A = 1.04-1.12) and moderate isotactic preference (P m = 0.56-0.72), with polymerization outcome correlating with ligand substituents.

Original languageEnglish
Pages (from-to)5977-5984
Number of pages8
JournalMacromolecules
Volume52
Issue number15
Early online date31 Jul 2019
DOIs
Publication statusPublished - 13 Aug 2019

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Equipment

  • Cite this