2 - Synthesis of tantalum and niobium fluoride compounds

Abstract

The variety of fluoride compounds that exist and the wide spectrum of their preparation methods are related to the properties of fluorine, and above all to fluorine's high electronegativity. Another peculiarity of the synthesis of fluoride compounds is their relatively low thermal stability and tendency to undergo hydrolysis and pyrolysis. These features are very common in the case of rare metal fluoride compounds. Thus, special conditions are required for the successful processing of fluoride compounds: special preparation of initial reagents, dry atmosphere, vacuum conditions, and so on. The synthesis of tantalum and niobium fluoride compounds is related to the fluorination of metals or oxides. The fluorination of both metals and oxides of niobium and tantalum can take place even at low temperatures; whereas, fluorination using ammonium fluoride and ammonium hydrofluoride can be performed only at higher temperatures. Synthesis of fluoride compounds is performed in various media, such as aqueous solutions, non-aqueous systems, and heterogeneous interactions.