Unexpected Formation of Copper Dimethylglyoxime Dimer from the Reaction of Cuprous Chloride and Tetradentate Buthylene-Bridged Diiminedioxime Ligand

Abstract

A reaction of a ligand 3,3′-(1,4-butanediyldinitrilo)bis(2-butanone)dioxime (BnH2 ) and CuCl yield green [Cu(H2 dmg)Cl(μ-Cl)]2 ,1. The dimethylglyoxime (H2 dmg) and CuIIions in 1 were in situ produced during the course of reaction and formed doubly chloro-bridged Cu(II) dimers. The geometry around copper ion is distorted square pyramidal. The weak intermolecular hydrogen bonds are observed in 1 giving 1D structure. The existence of two O-O distances of O2-O1= 2.922 and O4-O3= 2.910 indicates that these weak intermolecular hydrogen bonds are not equivalent. Hence doublet of the O-H stretching at 3302 and 3216 cm-1 are observed.