Structure of Nb8O10(OEt)20 and the nature of crystalline metal oxyalkoxides

NbO(OR)3 compounds with R=Me, i-Pr and n-Bu were synthesized through NbO(OEt)3 reesterification by other alcohols. Physico-chemical properties of the synthesized compounds were studied. Crystallization of liquid NbO(OEt)3 proceeds at a slow rate, yielding Nb8O10 (OEt)20 (1) formation. The IR spectra obtained testing to molecular association on account of all oxo- and part of OR-groups. The association nature of MO(OR)n molecula - derivatives of U and Cr subgroups - is discussed. X-ray structural analysis of (1) was carried out. Structure of metal-oxygen octamer framework was confirmed, interatomic distances, valence angles and atom coordinates were determined. Possibility of producing Nb, Y, In, Zr, Cl (etc.) crystal polynuclear oxo-alcoholates is discussed