Synthesis and structure of the useful starting material [Bu4N]3[Nb6Cl12(OSO2CF3)6]

The synthesis and characterization of the cluster [Bu4N]3[Nb6Cl12(OSO2CF3)6] is reported, and the metathesis of this cluster with [Bu4N]X resulted in the formation of the clusters [Bu4N]n[Nb6Cl12X6] (X=Cl−, Br−, I− and SCN−; n=3 or 4). The cluster [Bu4N]3[Nb6Cl12(OSO2CF3)6] crystallizes in the monoclinic space group C2/c (no. 15) with a=26.808(4), b=25.826(6), c=15.889(4) Å, β=91.96(2)°, V=10994(3) Å3, and Z=4. A refinement was based on 4105 (I>3.00σ(I)) observed reflections with 436 variable parameters had agreement parameters of R=0.087 and Rw=0.109. The structure consists of a slightly distorted metal octahedron surrounded by 12 edge-bridging chlorine atoms and six axial OSO2CF3 − groups. The average NbNb bond length is 2.947 Å, the average NbCl bond length is 2.429 Å, and the average NbO bond length is 2.15 Å. Vibrational and electronic spectra provide a means for monitoring the facile reaction chemistry of [Bu4N]3[Nb6Cl12(OSO2CF3)6].