Vibrational spectra of complexes of metals with dimethylacetamide

NMR of 19F has been used for studying the composition and structure of complex niobium fluorides obtained upon dissolution of NbF5 in C2H5OH and during interaction of Nb(OC2H5)5 with NbF5 or HF in ethyl alcohol. The formation has been observed of neutral molecules, complex anions and cations with different number of fluorine atoms in the metal coordination sphere. Introduction of amines into alcohol solutions of niobium ethoxyfluorides shifts the equilibrium towards the formation of [NbFsub(n)(OCsub(2)Hsub(5))]sub(6-n)sup(-). Transformation of the neutral complex trans-[NbF4(OC2H5)xC2H5OH]0 into anion cis-[NbF4(OC2H5)2]- in the presence of amine proceeds with a ligand dislocation. It has been shown that forms with cis-location of ethoxy-group dominate among niobium ethoxyfluoride anions