Niobium(V) fluoride
Introduction '''Niobium(V) fluoride''', also known as '''niobium pentafluoride''', is the inorganic compound with the formula NbF5.It is a colorless solid.
Preparation and structure Niobium pentafluoride is obtained by treatment of any niobium compound with fluorine::2 Nb  +  5 F2   →  2 NbF5:2 NbCl5  +  5 F2   →  2 NbF5  +  5 Cl2As shown by X-ray crystallography, the solid consists of tetramers NbF54.This structure is related to that for WOF4.
Reactions It reacts with hydrogen fluoride to give H2NbF7, a superacid. In hydrofluoric acid, NbF5 converts to NbF72- and NbF5O2-. The relative solubility of  (M = Nb, Ta) is the basis of the Marignac process for separation of Nb and Ta.NbCl5 forms a dimeric structure (edge-shared bioctahedron) in contrast to the corner-shared tetrameric structure of the fluoride.
External links *  NIST Standard Reference Database
References