Crystal Structure of (H3O)2[(UO2)2(SeO4)3(H2O)2](H2O)3.5

Crystals of (H3O)(2)[(UO2)(2)(SeO4)(3)(H2O)(2)](H2O)(3.5) were prepared from aqueous solutions by evaporation. The crystal structure [monoclinic system, space group P2(1)/m, a = 11.9402(11), b = 13.6452(14), c = 13.7271(12) angstrom, beta = 109.436(7)degrees, V = 2109.1(3) angstrom(3)] was solved by the direct method and refined to R-1 = 0.048 (wR(2) = 0.082) for 3677 reflections with vertical bar F-hkl vertical bar >= 4 sigma vertical bar F-hkl vertical bar. The structure consists of [(UO2)(2)(SeO4)(3)(H2O)(2)](2-) layers arranged parallel to the (010) plane. The layers are formed by uranium and selenium coordination polyhedra sharing common vertices and are linked with each other by hydrogen bonds through the H2O and H3O+ groups arranged between the layers.