Synthesis and X-ray diffraction study of cs3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] and Cs5[UO2(CH3COO)3]3[UO2(NCS)4(H2O)] · 2H2O

Abstract

Cs3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] (I) and Cs5[UO2(CH3COO)3]3[UO2 (NCS)4(H2O)] · 2H2O (II) have been synthesized via the reaction between uranyl acetate and cesium thiocyanate in aqueous solution. According to single-crystal X-ray diffraction data, both compounds crystallize in monoclinic system with the unit cell parameters a = 18.7036(5) A, b = 16.7787(3) A, c = 12.9636(3) A, β = 92.532(1)°, space group C2/c, Z = 4, R = 0.0434 (I); and a = 21.7843(3) A, b = 24.6436(5) A, c = 13.1942(2) A, β = 126.482(1)°, space group Cc, Z = 4, R = 0.0273 (II). Uranium-containing structural units of compound (I) are mononuclear [UO2(CH3COO)3]− and [UO2(CH3COO)(NCS)2(H2O)]− moieties, which correspond to the AB301 and AB01M31 crystallochemical groups (A = UO22+, B01 = CH3COO−, M1 = NCS− and H2O). The structure of compound II is built of [UO2(CH3COO)3]− and [UO2(NCS)4(H2O)]2− complexes, which belong to the AB301 and AM51 crystallochemical groups, respectively. Uranium-containing complexes in both structures are linked into a framework by hydrogen bonds and electrostatic interactions with cesium cations. The IR spectra of compounds I and II agree well with X-ray diffraction data.