Binuclear tungsten(V) oxo-complexes with 1,1-dithiolate ligands

In this paper we report the synthesis of some new oxo and sulphido bridged tungsten(V) complexes with N-ethylanilindithiocarbamate and N,N-methylcyclohexyldithiocarbamate as ligands. These complexes have been characterised by analytical, magnetochemical and spectral methods. The results permit us to assign the formulate: W₂O₃(LL)₄, W₂O₄(LL)₂, W₂O₂S₂(LL)₂ and W₂O₃S(LL)₂. The low magnetic moments observed in these complexes, are due either to an interaction through the bridging atoms or to a direct spin-spin interaction. IR and electronic absorption spectra of these complexes are sensitive to substitution of sulphur atoms into the bridge system. The systematic changes upon bridge modification are useful in characterizing the compounds and in clarifying assignments of W-O and W-S bridge stretching frequencies. The results are discussed on the basis of structural information available for tungsten complexes.