Organic compounds of niobium and tantalum: alcoholysis reactions of niobium and tantalum penta-alkoxides

Abstract

Reactions of niobium and tantalum penta-ethoxides with n- and isopropanols, n-, sec.- and tert.-butanols and tert.-pentanol have been studied. In order to make a comparative study of the reactivities of primary, sec.- and tert.-alcohols, the reactions of niobium and tantalum penta-alkoxides (methoxides, ethoxides and isopropoxides) with tert.-butanol, and niobium and tantalum penta-tert.-butoxides with alcohols (methanol, ethanol and isopropanol) have been studied and products of the type M(OBu^t)(OR)₄ (where M is niobium or tantalum) obtained. However, the reactions of penta-methoxides with tert.-butanol yield finally M(OBu^t)_1.5(OMe)_3.5. The identity of these mixed alkoxides has been established by distilling or subliming them under reduced pressure. Molecular weights of these mixed alkoxides were determined ebullioscopically in benzene.