Crystal and molecular structure of diaquadinitratouranyl dihydrate [UO2(NO3)2(H2O)2] · 2H2O

Single crystals of previously unknown diaquadinitratouranyl dihydrate [UO2(NO3)2(H2O)2] · 2H2O (I) were obtained by evaporation of aqueous solution of [UO2(NO3)2(H2O)2] · 4H2O containing nitric acid in air at ambient temperature. The structure of the complex was studied by X-ray diffraction analysis. Crystals are monoclinic, a = 7.6820(15) Å, b = 9.887(2) Å, c = 7.1990(14) Å, β = 105.08(3)°, space group P21/c, Z = 2, V = 527.95(18) Å3. Structural units of crystal are neutral centrosymmetrical molecular complexes [UO2(NO3)2(H2O)2] and crystal water molecules united by a hydrogen bond system. Certain structural and spectral characteristics of new complex I and known diaquadinitratouranyl complexes were compared.