Complexes of copper(II) nitrate and chloride with several bis(pyrazol-1-yl)methane derivatives have been prepared and characterized by spectroscopic (IR, UV-Vis) and electrochemical (solution conductivity measurements, cyclic voltammetry) techniques. The complexes react with bidentate (2,2'-bipyridyl and acetylacetone) and monodentate (triphenylphosphine, 1H-benzimidazole, 1H-benzotriazole, 3,5-dimethyl-1H-pyrazole) ligands forming mixed-ligand complexes. (c) 2006 Elsevier Ltd. All rights reserved.