PREPARATION AND STUDY OF SOME ANTIMONY AND BISMUTH TRIS-DITHIOCARBAMATE AND 5-COORDINATE MONOHALOBISDITHIOCARBAMATE DERIVATIVES

The complexes of antimony(III) and bismuth(III) with piperidinedithiocarbamate (Pipdtc), morpholinedithiocarbamate (Morphdtc) and thiomorpholinedithiocarbamate (Timdtc) of general formula M(Rdtc)3 have been prepared, and characterized by spectroscopic methods. The data show that the complexes have a distorted octahedral stereochemistry, this distortion being due to the stereochemically active lone-pair of electrons on the antimony and bismuth atoms. A new series of pentacoordinate complexes of general formula M(Rdtc)2X, M being antimony or bismuth, X a halogen and Rdtc the above dithiocarbamates, has been prepared by reacting the corresponding trisdithiocarbamates with chlorine, bromine and iodine. The compounds have been characterized by IR and electronic spectroscopy and molecular weight determinations. The infrared spectra suggest that each dithiocarbamate group coordinates as a bidentate ligand; the metal-halide and metal-sulphur stretching modes have also been assigned. The spectral data are discussed and compared with those of the corresponding trisdithiocarbamate derivatives. The molecular weight determinations indicate that the trisdithiocarbamate complexes are monomeric; for the monohalobisdithiocarbamates, the antimony derivatives are shown to be monomeric, while the bismuth derivatives tend to dimerize. © 1979.