POLYMERIC )(ETA(3)-S,ETA(1)-N)-(1,3-THIAZOLIDINE-2-THIONATO) TETRACOPPER(I))MONOTOLUENE SOLVATE] - ELECTROCHEMICAL SYNTHESIS, CHARACTERIZATION AND CRYSTAL-STRUCTURE AT 160 K

The preparation of the title compound, [{Cu(tzdt)}(4)] as the monotolu ene solvate, has been achieved electrochemically, in toluene, with a c opper anode, a platinum cathode and the parent ligand, 1,3-thiazolidin e-2-thione, (tzdtH), with tetrabutylammonium tetrafluoroborate as supp orting electrolyte. The colourless, diamagnetic complex crystallises i n a triclinic cell with a = 11.51(2), b = 11.80(2), c = 12.59(2) A, al pha = 116.03(6), beta = 100.42, gamma = 107.67(6)degrees, Z = 2, space group P ($) over bar 1, final R = 0.0331 from 3805 observed reflectio ns with F-o(2) > 2 sigma(F-o(2)). The structure consists of self-assem bled [{Cu(tzdt}(4)] tetramers which are sulfur bridged through the 'wi ng tip' copper(I) atoms into polymeric chains; the toluene molecules o ccupy space between the polymeric chains. The central cyclic Cu, clust er is butterfly shaped with Cu-Cu distances in the range 2.692(4)-2.88 2(5) Angstrom. The 'spinal' copper atoms have distorted trigonal S2N c oordination from three different ligands and the 'wing tip' atoms have distorted tetrahedral S3N coordination from three different ligands w ithin an individual tetramer plus an additional contact from a thionat o sulfur atom in an adjacent tetramer. The latter contacts generate as ymmetric, centrosymmetrically related Cu2S2 cores (Cu-S = 2.539(3) and 2.790(3) Angstrom), which link the 'wing tip' atoms of the tetrameric units into a polymeric chain. The remaining Cu-S distances are in the range 2.222(3)-2.461(4) Angstrom with the Cu-N distances in the range 1.993(4)-2.023(4) A. The four ligands in each tetramer consist of two mu(3)-S,N(eta(2)-S,eta(1)-N) and two mu(4)-S,N(eta(3)-S,eta(1)-N) bri dging species. The complex exhibits ligand centred irreversible redox behaviour, in acetonitrile, and is stable to atmospheric oxidation at room temperature. Thermal decomposition of the complex, to the metal, occurs in flowing air (60-1000 degrees C), with endothermic solvent de sorption, intermediate phase change and melting processes as well as e xothermic decomposition in static air (60-850 degrees C).