Synthesis, spectroscopic and structural characterization of Cu(II) derivatives of tris(pyrazol-1-yl)methanes

Abstract

The reaction between CuX 2 (X=ClO 4, NO 3, Cl, Br and CH 3COO) and excess of tris(pyrazol-1-yl)methane ligands L (L=CH(pz) 3, CH(4-Mepz) 3, CH(3,5-Me 2pz) 3, CH(3,4,5-Me 3pz) 3 or CH(3-Mepz) 2(5-Mepz)) yields [CuX 2(L)], [{CuX 2} 3(L 2) 2] or [Cu(L 2)]X 2-type complexes. The ligand to metal ratio is dependent on the number and disposition of the Me substituents on the azole-type ligand and mainly on the nature of the counter-ion X. All complexes have been characterized in the solid state as well as in solution (IR and UV spectra, and conductivity determinations). The solid-state structures of [Cu{(3,5-Me 2pz) 3CH} 2](NO 3) 2, [Cu{(3,5-Me 2pz) 3CH} 2](ClO 4) 2·0.5H 2O, [Cu{(3,4,5-Me 3pz) 3CH} 2](NO 3) 2·H 2O, [Cu{(4-Mepz) 3CH} 2]Br 2·3H 2O have been determined by single crystal X-ray studies.