Crystal structure of neptunium (5) aquachlorocomplex with cesium, CsNpO2Cl2(H2O)

Using the method of X-ray diffraction and IR spectroscopic analysis, crystal structure of neptunium (5) new complex of the composition Cs[NpO2Cl2(H2O)] is investigated. The crystals are monoclinic, crystal lattice parameters are: a=1.171(2), b=0.699(2), c=0.876(2) nm, γ=93.1(3) deg, space group P21(P21/n), Z=4, ρcalctd=4.55 g/cm3. The structure is determined using the heavy atom method and is specified to R0.139. The structure is built of infinite anion chains [NpO2Cl2(H2O)]nn- and cations Cs+. Somewhat distorted pentagonal bipyramide [NpO2Cl4(H2O)] is coordination polyhedron of neptunium. Np-O interatomic distances in oxocations NpO2+ are equal to 0.180(3) and 0.181(3) nm, O-Np-O angle is 176(2) deg. The average value of Np-Cl distances constitutes 0.287 nm