Synthesis and structural characterization of the benzimidazolate-bridged binuclear copper(II) complex with N,N'-bis(carboxymethyl)glycine

A benzimidazolate-bridged binuclear copper(II) complex with N,N'-bis(carboxymethyl)glycine, Na-3[Cu-2(BCMG)(2)Bzim]. 10H(2)O has been synthesized and its structure has been determined by X-ray single crystal diffraction. The N,N'-bis(carboxymethyl)glycinate trivalent anion (BCMG) acts as a tetradentate ligand to copper(II). Each copper atom is complexed by three oxygen atoms from carboxylates, one nitrogen atom from BCMG and one nitrogen atom from the benzimidazolate anion. The benzimidazolate anion bridges two copper atoms [Cu(1), Cu(2)], which are 5.716(7) Angstrom apart. Na+ ions are complexed by oxygen atoms from water molecules and carboxylates and bridged by several oxygen atoms. The geometry of coordination around copper atoms and Na(2) and Na(3) is an intermediate between trigonal bipyramidal (TBP) and tetragonal pyramidal (TP), but around Na(1) it is distorted octahedral. Copyright (C) 1996 Elsevier Science Ltd