CRYSTAL AND MOLECULAR STRUCTURE OF TRIS(ACETYLACETONATO)AQUOYTTERBIUM(3) HEMIBENZENE

The crystal structure of tris (acetylacetonato )aquoytterbium( III) hemibenzene, Yb(C5HO7O2)3(H2O)·0.5C6H6, has been determined from three-dimensional X-ray diffraction data. Two formula units are contained in a triclinic unit cell of space group and dimensions a = 8.728 ± 0.009 Å, b = 8.435 ± 0.009 Å, c = 15.623 ± 0.016 Å, α = 95.95 ± 0.02°, β = 107.72 ± 0.09°, and γ = 96.18 ± 0.09°. A total of 2625 intensities above background were collected by counter methods. The structure was refined by least-squares methods to a conventional R factor of 0.080; during the final cycle of refinement, corrections for anomalous dispersion were included. The ytterbium atom is surrounded by seven oxygen atoms at the vertices of a capped trigonal prism. These tris(acetylacetonato)aquoytterbium(III) molecules are linked in pairs by hydrogen bonds. The benzene molecule occupies a center of symmetry; all of the intermolecular contacts involving benzene carbon atoms and acetylacetonate carbon or oxygen atoms exceed 3.5 Å. © 1969, American Chemical Society. All rights reserved.