Crystal structure of chlorido-{1-(2,3-dimethyl-5-oxido-1-phenyl-1H-pyrazol-2-ium-4-yl-κO)-2-[3-methyl-5-oxo-1-phenyl-4,5-di-hydro-1H-pyrazol-4-yl-idene-κO]hydrazin-1-ido-κN (1)}copper(II) from laboratory X-ray powder data.

In the title compound, [Cu(C21H19N6O2)Cl], the Cu(II) atom is in a slightly distorted square-planar coordination involving two O atoms from the pyrazolone rings [Cu-O = 2.088 (10) and 1.975 (10) Å], an N atom of the azo group [Cu-N = 2.