Zinc(II) Homogeneous and Heterogeneous Species and Their Application for the Ring-Opening Polymerisation of rac-Lactide

✍ Scribed by Matthew D. Jones; Matthew G. Davidson; Callum G. Keir; Laura M. Hughes; Mary F. Mahon; David C. Apperley

• Book ID: 102168886
• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 454 KB
• Volume: 2009
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/ejic.200801049

✦ Synopsis

Abstract

Schiff base ligands (L1H–L8H) have been prepared and complexed to Zn^II^ centres. All eight complexes have been characterised by single‐crystal X‐ray diffraction methods, multinuclear NMR spectroscopy and elemental analysis. It was shown that for L1H and L2H trimetallic complexes of the form Zn~3~(OAc)~4~(L1–2)~2~ were isolated. However, for L3H to L7H monometallic complexes were formed, Zn(L3–7)~2~. For L8H a trimetallic complex was also isolated with the same stoichiometry as Zn~3~(OAc)~4~(L1–2)~2~ but a different coordination motif was detected. The Schiff base ligand L1H was anchored to silica and treated with Zn(OAc)~2~·2H~2~O to form the heterogeneous Zn^II^ system. This was characterised by ^13^C{^1^H} CP/MAS NMR spectroscopy. All homogeneous and heterogeneous catalysts were assessed for the ring‐opening polymerisation of rac‐lactide at 130 °C in the absence of solvent, using unsublimed monomer. All catalysts offered good conversions and a moderate degree of control.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)