Synthesis and characterization of dithiocarbonate derivatives of zinc and cadmium bis(dithiocarbamates)

The mixed-ligand complexes [NBun4][Zn(S2CNMe2)2(S2COEt)]1, [NBun4][Cd(S2CNEt2)2(S2COEt)]2 and [PPh4][Cd(S2CNEt2)2(S2COEt)]3 have been prepared by direct addition of zinc and cadmium bis(dithiocarbamate) to the tetraalkylammonium or tetraphenylphosphonium dithiocarbonate salt in acetone at room temperature. The compounds were characterized by elemental analysis and infrared, Raman, and 1H NMR spectroscopy. The crystal structures of 1 and 3 were determined: 1, orthorhombic, space group Pbca(no. 61), a= 20.140(5), b= 16.570(4), c= 21.453(5)A and Z= 8; 3, orthorhombic, space group Pna21(no. 33), a= 19.027(5), b= 13.829(3), c= 15.938(4)A and Z= 4. The environment about zinc is a distorted trigonal bipyramid with a monodentate dithiocarbonate ligand in an equatorial position and the dithiocarbamate ligands spanning one axial and one equatorial position each. The cadmium environment is a distorted six-co-ordinate trigonal prism. The metal–sulfur modes are assigned empirically at 218 (Zn–S) and at 165 cm–1(Cd–S). The thermal degradation of solids 1 and 2 affords ZnS and CdS, respectively.