The synthesis and the spectroscopic characterization of fluoride-alkoxides of niobium and tantalum in the highest oxidation state are reported. Suspensions of MF5 (M= Nb, Ta) in a chlorinated solvent reacted with up to three equivalents of ROSiMe3 (R= Me, Et, Ph) to afford polynuclear derivatives and variable amounts of FSiMe3. Thus MF4 (OR)(R= Et, Ph) and MF3 (OR) 2 were obtained by selective 1: 1 and 1: 2 reactions almost exclusively as single ...
