The oxidation of dithiocarbamato complexes of nickel, copper and zinc

Abstract

AbstractOxidation of N,N‐di‐n‐butyldithiocarbamato (bu2dtc) complexes of Cu(I), Ni(II), Zn(II), Cd(II) and Hg(II) is reported. Oxidation of Ni(bu2dtc)2 with Cl2, Br2, or of NiX2 (X = Cl, Br, NO3) with N,N,N′,N′‐tetra‐n‐butylthiuram disulfide (bu4tds) gives complexes of composition [Ni(bu2dtc)3]X. These compounds are diamagnetic and dissolve in nitrobenzene as 1:1 electrolytes, their UV spectra resemble that of the iso‐electronic Co(bu2dtc)3. The experimental data are in accord with the assumption that in these compounds Ni(IV) flow spin d6) is surrounded by 6 S atoms in octahedral symmetry. The analogous selenium compound tris (N, N‐di‐n‐butyldiselenocarbamato) nickel(IV) bromide, having the same properties as the thio compounds, can also be prepared. Oxidation of Cu(bu2dtc) with Cl2 or Br2 yields paramagnetic products with the composition CuX3(bu2dtc), in which Cu also has the formal oxidation number + 4, but the structure of these compounds is still obscure. Oxidation of Zn(bu2dtc)2 and the corresponding Cd and Hg compounds yields products, the analysis of which suggests the composition MX2(bu2dtc)2 (M = Zn, Cd or Hg, X = Br or I), but infrared studies indicate that the dithiocarbamato ligands of the starting substances are oxidized to bu4tds, which in the reaction products is coordinated to the metal in its normal oxidation state + 2.