Crystal structure of a trigonal polymorph of aqua­dioxidobis(pentane-2,4-dionato-κ(2) O,O′)uranium(VI)

The title compound, [UO(2)(acac)(2)(H(2)O)] consists of a uran­yl(VI) unit ([O=U=O](2+)) coordinated to two monoanionic acetyl­acetonate (acac, C(5)H(7)O(2)) ligands and one water mol­ecule. The asymmetric unit includes a one-half of a uranium atom, one oxido ion, one-half of a water mol­ecule and one acac ligand. The coordination about the uranium atom is distorted penta­gonal–bipyramidal. The acac ligands and O(w) atom comprise the equatorial plane, while the uranyl O atoms occupy the axial positions. Inter­molecular hydrogen bonding between complexes results in the formation of two-dimensional hexa­gonal void channels along the c-axis direction with a diameter of 6.7 Å. The monoclinic (P2(1)/c space group) polymorph was reported by Alcock & Flanders [(1987). Acta Cryst. C43, 1480–1483].