Synthesis and Complexation Behavior of a Dialkoxo-bridged Dinuclear Copper(II) Complex with Schiff Base Ligand

A unprecedented dinuclear copper(Ⅱ) complex, [Cu2(L2)2] (H2L2=4-(N,N'-diethylamino)salicylaldehyde O-(2-hydroxyethyl)oxime), has been synthesized through the complexation of copper(Ⅱ) acetate monohydrate with ligand H2L1 (H2L1=5,5'-di(N,N'-diethylamino)-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 complex possessing a Cu-O-Cu-O four-membered ring core instead of the usually desired Salen-type bisoxime Cu-N2O2 complex. CCDC: 670381.