CRYSTAL STRUCTURES OF TRIS-HEXAFLUORO- ACETYLACETONATES OF ALUMINUM AND SCANDIUM
A. I. Smolentsev, K. V. Zherikova, M. S. Trusov, P. A. Stabnikov, D. Y. Naumov, S. V. Borisov
Keywords: aluminum, scandium, ?-diketonates, single crystal X-ray crystallography, crystal chemistry
Pages: 1108-1115
Abstract
The structures of tris-hexafluoroacetylacetonates Al(hfa)3 and Sc(hfa)3·H2O are determined by single crystal X-ray crystallography (Bruker-Nonius X8 Apex diffractometer, MoKα radiation, T = 150(2) K). The Al(hfa)3 complex is trigonal, a = 17.8944(11) Å, c = 12.4061(11) Å, P-3с1 space group, V = 3440.3(4) Å3, Z = 6, R = 0.076. The Sc(hfa)3·H2O complex is monoclinic, a = 16.0926(4) Å, b = 14.7980(3) Å, c = 24.4020(5) Å, β = 125.641(1)°, P21/c space group, V = 4722.54(18) Å3, Z = 8, R = 0.060. The structures of the complexes are formed by neutral molecules; the coordination environment of the metal atom involves six oxygen atoms of three β-diketone ligands (Al(hfa)3) and, additionally, a water oxygen atom (Sc(hfa)3·H2O). The shortest Al…Al distance is 6.203(6) Å. The Sc(hfa)3·H2O molecules are joined in dimers by hydrogen bonds with Sc…Sc separations of 5.6992(8) Å and 5.6853(8) Å. In the crystals, the molecules are joined by van der Waals interactions, moreover, there are intermolecular contacts F…H ~ 2.5 Å in the structure of Sc(hfa)3·H2O.
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