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- an d SCN-; n = 3 or 4). The cluster [Bu4N](3)[Nb6Cl12(OSO2CF3)(6)] crystallize s in the monodinic space group C2/c (no. 15) with a = 26.808(4), b = 25.826 (6), c = 15.889(4) Angstrom, beta = 91.96(2)degrees V = 10994(3) Angstrom(3 ), and Z = 4. A refinement was based on 4105 (I > 3.00 sigma(I)) observed r eflections with 436 variable parameters had agreement parameters of R = 0.0 87 and R-w = 0.109. The structure consists of a slightly distorted metal oc tahedron surrounded by 12 edge-bridging chlorine atoms and six axial OSO2CF 3-, groups. The average Nb-Nb bond length is 2.947 Angstrom the average Nb- Cl bond length is 2.429 Angstrom, and the average Nb-O bond length is 2.15 Angstrom. Vibrational and electronic spectra provide a means for monitoring the facile reaction chemistry of [Bu4N](3)[Nb6Cl12(OSO2CF3)(6)]. (C) 2000 Elsevier Science S.A. All rights reserved.