Synthesis and Electrochemistry of Schiff Base Cobalt(III) Complexes and Their Catalytic Activity for Copolymerization of Epoxide and Carbon Dioxide

✍ Scribed by Xiuli Zhuang; Kenichi Oyaizu; Yongsheng Niu; Kenichiroh Koshika; Xuesi Chen; Hiroyuki Nishide

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 306 KB
• Volume: 211
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.200900472

✦ Synopsis

Abstract

A series of cobalt complexes with N,N,O,O‐tetradentate Schiff base ligands were prepared. All the complexes were characterized by spectroscopy and electrochemical methods. An X‐ray crystal structure analysis revealed that L^1^‐Co^III^‐dnp was monomeric with a six‐coordinated central cobalt(III) atom in the solid state. The complexes were employed as catalysts for the alternating copolymerization of CO~2~ and racemic propylene oxide. End group analysis of the resulting polymer provided strong evidence for a monomer insertion mechanism for the propagation step. The catalytic activity was interpreted using the redox potential of cobalt(II/III) for the L**‐Co**^III^‐dnp complexes, which offered a measure of the bond strength, or the degree of inertness of the axial ligand, to promote or suppress the monomer insertion.

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