TRANS-BIS[(THIOCYANATO-S)(1-METHYLIMIDAZOLINE-2(3H)-THIONE)-MU-2-(1-METHYLIMIDAZOLINE-2(3H)-THIONE)COPPER(I)] - PREPARATION, THERMAL-ANALYSIS AND CRYSTAL-STRUCTURE

1-Methylimidazoline-2(3H)-thione (mimtH) and copper(I) thiocyanate in refluxing ethanol-acetonitrile produce a colourless, diamagnetic complex, [Cu2(mimtH)4(SCN)2], which crystallises in an orthorhombic cell (a = 8.0724(3), b = 15.9545(6), c = 21.3357(8) angstrom), space group = Pbca, Z = 4, final R = 0.0319 from 2427 observed reflections F > 4-sigma-c(F)). In the dimeric complex the copper(I) atoms are pseudo-tetrahedrally coordinated by pairs of, respectively, asymmetrically-mu-2-S bridging mimtH, terminal monodentate-S mimtH, (Cu-S = 2.290(1) angstrom), and terminal monodentate-S thiocyanate, (Cu-S = 2.332(1) angstrom). Each pair of ligands is trans-related to its partner across crystallographic centres of symmetry, consequently, each copper(I) atom has an identical S4 donor set with angles at the metal ranging from 95.9(1)-degrees to 121.8(1)-degrees. The centro-symmetric Cu2S2 core is rhomboid with Cu-S = 2.377(1) and 2.457(1) angstrom, Cu-S(br)-Cu = 72.6(1)-degrees and Cu---Cu, S(br)---S(br) separation distances of 2.861(1) and 3.897(2) angstrom, respectively. Thermal decomposition of the complex in flowing air, (133-1000-degrees-C), involves de-sulfurisation of mimtH and thiocyanate with concomitant production of copper(II) sulfide followed by oxidation to copper(II) oxide.