New coordination compounds of copper(I) have been synthesized: [Cu2L 2 1 Cl2] (I) and [Cu2(HL2)2Br2] (II), where L1 is methyl 3-[(3,5-dimethyl-pyrazole-1-carbothioyl)-amino]-propionate, and HL2 is ethyl [(3,5-dimethyl-pyrazole-1-carbothioyl)-amino]-acetate. X-ray diffraction analysis showed that the crystal structures of these compounds are built from binuclear molecules. The L1 and HL2 molecules perform the bridging tridentate cyclic function, which results in a closure of two five-membered chelate cycles CuN2SC and metallocycle Cu2S2. Each Cu atom coordinates the N atom of the pyrazole ring, the halogen atom (Cl in I and Br in II), and two S atoms, thus forming a distorted tetrahedron. The Cu2S2 metallocycles, the CuN2SC chelate cycles, and the pyrazole rings are flat. Both CuN2SC chelate cycles are almost perpendicular to the Cu2S2 metallocycle and form a chair conformation. Redox reactions in CuCl2·2H2O-L1-ethanol and CuBr2-HL2-ethanol systems were examined by EPR spectroscopy.