Crystal structure of Aquatetrakis(N-formylpiperidine)dioxouranium(VI) Bisperchlorate

Abstract

The crystal structure of the title compound, [UO₂{OCHN(CH₂)₅}₄(H₂O)] (ClO₄)₂, has been determined by single-crystal X-ray diffraction at 295 K and refined by least squares to a residual of 0.051 for 3113 'observed' reflections. Crystals are monoclinic, C2/c, a 16.945(2), b 12.711(2), c 17.304(2)Ǻ, β 107.76(1)°, Z 4. The uranyl moiety [U=O, 1.76(2)Ǻ] is five-coordinated in the equatorial plane by the water molecule [U-O, 2.436(8)Ǻ] and four organic ligands [U-O, 2.379(8), 2.396(13)Ǻ]. The angles O-U-O in the equatorial plane range from 70.3(3) to 73.6(3)°; O=U-0 range between 86.7 and 95.3°. The angle O=U=O is 177.8(3)°. The stereochemistry of seven-coordinate uranyl compounds is examined by using repulsion theory.