MONODENTATE SUBSTITUTION-REACTIONS OF [MO2(CN)4]N- TYPE COMPLEXES - THE CRYSTAL-STRUCTURE OF THE SODIUM THIOCYANATE ADDUCT OF TETRAMETHYLAMMONIUM TETRACYANOOXOTHIOCYANATO-TUNGSTATE(IV)

The crystal structure of (Me4N)3[WO(CN)4(NCS)]·NaNCS was determined from three-dimensional x-ray diffraction data. The dark blue crystals are monoclinic, space group C2/m, with cell dimensions a=13.105(4), b=12.688(2), c=18.871(3) Å, β=100.4(8)°, z=4 and D=1.46 g cm-3. Anisotropic refinement of 1333 observed reflections converged to R=0.068. The [WO(CN)4(NCS)]3- ion is a distorted octahedron with the tungsten atom displaced by 0.35 Å out of the plane formed by the four cyano ligands, towards the oxo ligand. The coordinated thiocyanate ligand is bonded to the tungsten atom via the nitrogen atom trans to the oxo ligand. Bond distances found: W-CNav=2.14(3), W-O=1.61(2) and W-NCS=2.23(2) Å. The compound crystallizes as an adduct with an additional thiocyanate anion, ionically bonded to a severely disordered sodium cation. The results correlate with available data from similar complexes. © 1990 Chapman and Hall Ltd.