Tris(3,5-dimethylpyrazole)copper(II) nitrate (A) is a catalyst for mild oxidation of various organic substrates. It acts as catalyst for conversion of benzylamine to benzaldehyde in the presence of hydrogen peroxide. Various benzylic alcohols are converted to corresponding aldehydes and acids by the catalytic amount of the complex (A) with hydrogen peroxide at room temperature. The complex also catalyses dimerisation of 2,6-dimethylphenol and thiophenol. The thermal decomposition of tris(3,5-dimethylpyrazole)copper(II) nitrate at 500degreesC gives CuO having the monoclinic crystal system. The cyclic voltammogram of the complex tris-(3,5-dimethylpyrazole)copper(II) nitrate shows a quasi-reversible redox cycle at - 101 mV (E-1/2) versus the Ag/AgCl electrode (+ve scan; scan speed 100 mV/s). The DeltaE between anodic and cathodic peaks is 110 mV (i(pa)/i(pc) = 1.2). (C) 2004 Elsevier B.V. All rights reserved.