SYNTHESES, CHARACTERIZATION AND CRYSTAL-STRUCTURES OF METAL-COMPLEXES OF A NOVEL 1.2-DITHIOLATE LIGAND, 6,7-DIHYDRO-6-METHYLENE-5H-1,4-DITHIEPINE-2,3-DITHIOL

A series of [NR(4)] [M(dpdt)(2)] (R = Bu, M = Ni 2, Au 3 or Cu 4; R = Me, M = Ni 5; H(2)dpdt = 6,7-dihydro-6-methylene-5H-1,4-dithiepine-2,3-dithiol) complexes have been synthesized. Magnetic susceptibility measurements indicate that the gold 3 and copper 4 complexes are diamagnetic, whilst the nickel salt 2 is paramagnetic over the temperature range studied (290-22 K). The solution redox properties are consistent with a 1,2-dithiolene structure for these compounds. Single crystal X-ray analysis on compounds 2-4 revealed crystal-packing structures consisting of two crystallographically independent [M(dpdt)(2)](-) moieties possessing square-planar geometry, in which there are no intermolecular S ... S contacts shorter than the sum of the van der Waals radii (3.70 Angstrom).