Synthesis and structure of [UO2(SeO4)(C2H4N4)2] · 0.5H2O

The single-crystal X-ray diffraction analysis of [UO2(SeO4)(C2H4N4)2] · 0.5H2O (I) is performed. The crystals are monoclinic: space group C2/c, Z = 8, a = 19.035(2), b = 7.1326(8), c = 21.477(2) Å, β = 109.683(4)°. The main structural units of the crystal are chains of [UO2(SeO4)(C2H4N4)2]. Compound I belongs to the crystal-chemical group AT3M21 (A = UO22+, T3 = SeO42−, M1 is a cyanoguanidine molecule) of the uranyl complexes. The chains are united into three-dimensional framework through hydrogen bonds involving the oxygen atoms of the selenate and uranyl groups, the nitrogen atoms of cyanoguanidine, and the hydrogen atoms of the cyanoguanidine or water molecules.