Acta Crystallographica Section E (Dec 2011)
cyclo-Tetra-μ-oxido-tetrakis[(acetylacetonato-κ2O,O′)bis(ethanolato-κO)niobium(V)]
Abstract
The asymmetric unit of the title tetranuclear niobium(V) compound, [Nb4(C2H5O)8(C5H7O2)4O4], contains two NbV atoms, two bridging O atoms, two acetylacetonate and four ethanolate ligands. Each NbV atom is six-coordinated by the bridging O atoms, two ethanolate and one chelating acetylacetonate ligands. The Nb—O distances vary between 1.817 (2) and 2.201 (2) Å and the O—Nb—O angles vary between 78.88 (8) and 102.78 (9)°, illustrating the significant distortion from ideal ocahedral geometry. The rest of the tetranuclear unit is generated through an inversion centre. The C atoms of two of the ethanolate molecules are disordered over two sites [occupancy ratio 0.601 (12):0.399 (12)].