Bis(phenyl-β-diketonato)titanium(IV) ethoxide complexes: Ring-opening polymerization of l-lactide by solvent-free microwave irradiation. (1st January 2022)

• Record Type: Journal Article
• Authors: Lord, Rianne M.; Janeway, Felix D.; Bird, Laura; McGowan, Patrick C.
• Is Part Of: Polyhedron. Volume 211(2022)
• Publication Date: 2022-01-01
• Subjects: β-Diketonate ligands -- Polymerization -- Titanium; Chemistry, Inorganic -- Periodicals; Chimie inorganique -- Périodiques; Organometaalverbindingen; Anorganische chemie; 546.05
• DOI: 10.1016/j.poly.2021.115520
• Languages: English
• ISSNs: 0277-5387

Abstract

Graphical abstract: Abstract: A range of functionalized bis(phenyl-β-diketonato)titanium(IV) ethoxide complexes of the type [Ti(L)2 (OEt)2 ], containing two asymmetric or symmetric phenyl-β-diketonate ligands (L), have been synthesized and fully characterized. Single crystal X-ray diffraction has been used to confirm that all structures crystallize with the ethoxide ancillary ligands in a cis arrangement and NMR spectra show characteristic ligand rearrangement in solution. The complexes have been screened as catalysts in the ring-opening polymerization (ROP) of l -lactide (L-LA) to yield polylactide (PLA), by using microwave (MW) and conventional heating. The resulting polymers have high molecular weights but a high polydispersity index (PDI) which is suggestive of transesterification. However, unlike conventional heating methods, the polymerization by MW reaction leads to a retention in stereochemistry of the resulting polymer in significantly shorter time periods.