Study on Synthesis and Crystal Structure of an Unexpected Dialkoxo-Bridged Dinuclear Cu(II) Complex

Abstract

An unprecedented dinuclear copper(II) complex, [Cu₂(L²)₂] (H₂L² = 3-Methoxysalicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized via the complexation of copper(II) acetate monohydrate with unsymmetrical Salen-type ligand H₂L¹ (H₂L¹ = 3-Methoxy-2,2′-[ethylenedioxybis(nitrilomethylidyne)]diphenol). The crystal structure of the copper(II) complex has been determined by single-crystal X-ray diffraction method. The catalysis of copper(II) ions results in the unexpected cleavage of one of the N˭O bonds in the ligand H₂L¹, giving a novel dialkoxo-bridged dinuclear copper(II) complex possessing a Cu˭O˭Cu˭O four-membered ring core instead of the usually desired Salen-type bisoxime Cu˭N₂O₂ mononuclear complex.

Keywords:

• complexation behavior
• copper(II) complex
• crystal structure
• synthesis
• unsymmetrical Salen-type ligand

Acknowledgments

This work was supported by the Foundation of the Education Department of Gansu Province and the ‘Jing Lan’ Talent Engineering Funds of Lanzhou Jiaotong University, which are gratefully acknowledged.