Anionic halide and isothiocyanate adducts of zinc and cadmium dithiocarbamates

Abstract

The mixed-ligand complexes [NEt₄][Zn(S₂CNMe₂)₂X](X = Cl, Br, or NCS) and [NR₄][Cd(S₂CNEt₂)₂X](R = Et, X = Cl, Br, or NCS; R = Buⁿ, X = I) have been prepared by reaction of zinc and cadmium bis(dithiocarbamate) with the tetraalkylammonium salt of the halide or thiocyanate in acetone at room temperature. The single-crystal X-ray structures of [NEt₄][Zn(S₂CNMe₂)₂(NCS)]1 and [NEt₄][Cd(S₂CNEt₂)₂(NCS)]2 were determined: 1, monoclinic, space group P2₁/n, a= 9.447(1), b= 16.661(2), c= 15.807(1)Å, β= 97.10(1)° and Z=4; 2, orthorhombic, space group P2₁2₁2₁, a= 16.213(1), b= 17.501(2), c= 10.243(1)Å and Z= 4. The central Zn and Cd atoms show distorted trigonal-bipyramidal co-ordination geometry with the thiocyanate N atom occupying an equatorial position and the dithiocarbamate ligands spanning one axial and one equatorial position each. The infrared and Raman spectra (2100–50 cm^–1) of the complexes are discussed. The metal–sulfur stretching frequencies are assigned in the ranges 226–205 (Zn–S) and 203–145 cm^–1(Cd–S), respectively.