Crystal structure of UO2SO4·2.5H2O: Full anisotropic refinement and vibration characteristics

UO2SO4·2.5H2O is monoclinic, space group P21/c (No. 14), unit-cell parameters of a = 6.7260(1)Å, b = 12.4210(2)Å, c = 16.8270(3)Å, β = 90.781(1)° with unit-cell volume V = 1405.66(4)Å3, Z = 8, Dcalc = 3.84 g/cm3. Two distinct uranium atoms, present as uranyl (UO2)2+, forming uranyl pentagonal bipyramids, two distinct sulfur atoms, forming sulfate tetrahedra and 17 oxygen atoms are present in the asymmetric part of its unit-cell. Two of oxygen atoms are water molecules bonded to the uranyl cation and one is water molecule bonded only by hydrogen-bonding. Crystal structure was refined fully anisotropically. Vibration modes of each molecular unit in Raman and infrared spectra were tentatively assigned and discussed, regarding refined structure. Inferred U–O lengths and hydrogen bond lengths are consistent with the crystal structure refinement.