Organic compounds of niobium: reactions of niobium penta-alkoxides with acyl halides

Abstract

Compounds Nb(OEt)₄X, Nb(OEt)₃X₂, Nb(OEt)₂X₃ · CH₃COOEt and Nb(OEt)Cl₄ · CH₃COOEt, NbOBr₃ · CH₃COOEt (where X is chloride or bromide) have been isolated by the reactions of niobium penta-ethoxide with acetyl chloride and bromide. The reactions of niobium penta-isopropoxide and tert.-butoxide with acyl halides in equimolar ratios yield products of the type Nb(OR)₄X; the products with excess of acyl halides corresponds to NbOX₃.CH₃COOR. However, the reaction in the case of penta-tert.-butoxide and acetyl chloride yielded finally NbO(OAc)_0.75Cl_2.25 · CH₃COOBu^t. The reaction of niobium penta-ethoxide with dry hydrogen chloride gas yielded triethoxide dichloride derivative. Only niobium tetra-alkoxide monochloride derivatives could be distilled or sublimed and these were found to be dimeric in boiling benzene.