Reaction of ammonium
thiocyanate with dihalocarbonyls of molybdenum and
tungsten(11) leads to the
elimination of ammonium chloride and the formation of a dithiocyanatocarbonyl
complex of the transition metal. Although the thiocyanatocarbonyls
themselves have not been isolated in a pure state, a number of substituted
derivatives with phosphorus donor ligands have been prepared and characterized.
In general these complexes are less stable than the corresponding carbonyl
halide derivatives.