μ-Nitridokomplexe von Wolfram(VI) Die Kristallstruktur von PPh4[W2NCl10]/ μ-Nitrido Complexes of Tungsten(VI) The Crystal Structure of PPh4[W2NCl10]

Abstract

Abstract W2NCl9 was obtained as a brilliant red crystal powder from tungsten hexachloride and tris(trimethylsilyl)amine. According to its IR spectrum it has dimeric molecules [W2NCl9]2 with bridging chlorine atoms. Its reaction with tetraphenylphosphonium chloride yields PPh4[W2NCl10], and with phosphorus oxide chloride W2NCl9 ·OPCl3 is obtained; both are soluble in dichlorom ethane. The crystal structure of PPh4[W2NCl10] was determined by X-ray diffraction (2521 observed reflexions. R = 0.065). Crystal data: triclinic, space group P1̄, Z = 2, a = 1125.7, b - 1278.2, c = 1347.8 pm, α = 110.08, β = 94.55, γ = 111.55°. The structure consists of PPh4ⓛ ions which are arranged to (PPh4 ⓛ)2 pairs about inversion centres, and of [W2NCl10]⃝ anions. The latter possess an almost linear W NW group (173°) with slightly different WN bond lengths of 179 and 188 pm corresponding to double bonds. Each tungsten atom has an octahedral coordination. The WCl bonds trans to the nitrido ligand are about 9 pm longer than the bonds in the cis positions.