X-Ray crystal structure of bis(N-ethylpyridinum) bis[4,5-dimercapto-1,3-dithiole-2-thionato(2–)]cuprate(II) and electrical properties of its oxidized salts

Abstract

A single-crystal X-ray structure analysis has been performed for the complex bis(N-ethylpyridinium) bis[4,5-dimercapto-1,3-dithiole-2-thionato(2–)]cuprate(II). The crystals are monoclinic, space group C2/m, with Z= 4, a= 20.04(2), b= 14.56(2), c= 10.19(1)Å, and β= 109.2(1)°. Block-diagonal least-squares refinement, based on 1 882 independent reflections with |F_∘| > 3σ(F), converged at R= 0.077. The geometry around the copper atom is greatly distorted from a square-planar one, with a dihedral angle of 57.3° between the dithiolato ligand planes. While the complex behaves almost as an insulator, with an electrical conductivity of 7.1 × 10^–10S cm^–1 measured for a compacted pellet at 25 °C, some partially oxidized bis[4,5-dimercapto-1,3-dithiole-2-thionato(2–)]copper complexes exhibit increased conductivities of 10^–6–10^–5S cm^–1.