The weakly coordinating perchlorate group in bis(N,N'-dimethylethylenediamine-κ2N,N')bis(perchlorato-κO)copper(II) studied at 100, 250 and 400 K.

The crystal structure of the title compound, [Cu(ClO(4))(2)(C(4)H(12)N(2))(2)], (I), is reported at 100, 250 and 400 K. The Cu(II) cation in this complex is coordinated in a distorted octahedral mode characteristic of Jahn-Teller systems. The coordination of the perchlorate ligands via longer, and presumably weaker, axial Cu-O distances varies significantly as a function of temperature. One of the Cu-O distances increases between 100 and 250 K, and one of the Cu-O-Cl angles expands between 250 and 400 K. At all temperatures, the complex forms a two-dimensional N-H···O hydrogen-bond network in the (001) plane.