X-ray diffraction study of copper(I) thiourea complexes formed in sulfate-containing acid solutions

Abstract

The formation of three different copper(I) thiourea complexes in sulfate-containing acid solutions was observed. The ratio between CuI and thiourea (tu) in these complexes depends on the amount of thiourea and copper sulfate in the solution. The crystal and molecular structure of a new complex, [Cu_2(tu)_6](SO_4)\cdotH_2O, was determined, and the formation and structures of [Cu_2(tu)_5](SO_4)\cdot3H_2O and [Cu_4(tu)_7](SO_4)_2\cdotH_2O were confirmed. The compound [Cu_2(tu)_6](SO_4)\cdotH_2O crystallizes in the P\overline 1 space group, with a = 11.079 (2), b = 11.262 (1), c = 12.195 (2) Å, \alpha = 64.84 (1), \beta = 76.12 (1), \gamma = 66.06 (1)°, and Z = 2. The Cu-thiourea complex is arranged as a CuI tetranuclear ion, [Cu_4(tu)_{12}]^{4+}, sited on a crystallographic inversion center. All copper ions are in a tetrahedral coordination with thiourea ligands and located at alternate sites on an eight-membered, crown-like ring.