Crystal and molecular structure of a crystal solvate of cesium tris(pivaloyltrifluoroacetonato)dioxouranate, Cs[UO2(Bu t COCHCOCF3)3]·1.5C6H6·H2O

Abstract

The crystal and molecular structure of cesium tris(pivaloyltrifluoroacetonato)uranylate prepared in the form of a crystal solvate Cs[UO2(Bu t COCHCOCF3)3]·1.5C6H6·H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system, a = 26.9099(9), b = 13.1549(4), c = 24.4586(8) A, β = 90.418(2)°, V = 8658.0(5) A3 (at 100 K), Z = 8, space group C2/c. Of the three β-diketonate ligands, two are coordinated to the uranyl ion in the bidentate fashion, and the third ligand, in the monodentate fashion, so that the equatorial coordination number of the uranyl ion is 5. The crystal structure is built of sandwich-type dimers in which two cesium cations are arranged between two tris(pivaloyltrifluoroacetonato)uranylate anions. The coordination sphere of the cesium cation is built of oxygen atoms of the β-diketone and uranyl groups, fluorine atom of the CF3 group, and π-coordinated benzene molecule. In addition, 0.5 benzene molecule and one water molecule (per formula unit) occupy structural voids.