Bis[1,1-dimethylbiguanide(1-)-κ2N2,N5]copper(II) monohydrate

The crystal structure of the title compound, [Cu(C4H10N5)(2)] .-H2O, contains two independent copper N,N-dimethylbiguanide complex units, each with square-planar coordination of the Cu atom by four N atoms. The two complexes have different symmetry, with one Cu atom lying on an inversion centre and the other on a twofold rotation axis. The Cu - N bond lengths are 1.923 (2) and 1.950 (2) Angstrom in the centrosymmetric complex, and 1.928 (2) and 1.938 (2) Angstrom in the noncentrosymmetric complex. The crystal structure is stabilized by N - H...O, O - H...N and N - H...N hydrogen bonds; each water molecule forms four hydrogen bonds involving three different Cu complexes.