ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

New heteroscorpionate lanthanide complexes for ring-opening polymerisation of ε-caprolactone and rac-lactide

Alberto Scrivanti, Marco Bortoluzzi, and Mattia Gatto

Dipartimento di Scienze Molecolari e Nanosistemi, Universit`a Ca’ Foscari Venezia, Dorsoduro 2137, 30123 Venezia, Italy

E-mail: scrivanti@unive.it

Abstract: Yttrium and lanthanum amido-complexes with bis(pyrazol-1-yl)acetates in their coordination spheres were studied as the catalysts in ε-caprolactone and lactide ring-opening polymerisation. A high molecular mass poly(ε-caprolactone) (PCL) was obtained in almost quantitative yield under mild conditions. rac-Lactide polymerisations were less efficient and required quite harsh experimental conditions to obtain atactic PLA samples with moderate yields. The average chain-length of PCL was dependent upon the choice of the metal centre and the presence of substituents on the pyrazole rings of the ancillary ligand. The ground-state geometries of the complexes and the first stages of ε-caprolactone polymerisation were computationally modelled by means of DFT calculations.

Keywords: ROP – poly(ε-caprolactone) – polylactic acid – yttrium – lanthanum

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0144

Chemical Papers 70 (1) 53–60 (2016)