Single crystals of [UO2(OH)(C6NO2H4K6NO2H5)] are synthesized and studied by X-ray diffraction. The compound is crystallized in the monoclinic system with space group P2(1)/n and has the following unit cell parameters: a = 8.789(1) angstrom, b = 16.635(7) angstrom, c = 9.238(1) angstrom, beta = 97.89(1)degrees, and R-1 = 0.0614. The main structural units of the crystal are chains whose composition coincides with that of the compound and which are assigned to the crystal-chemical group AM(2)B(2)M(1) (A = UO22+, M-2 = OH-, and B-2 and M-1 are isonicotinic acid molecules or isonicotinate ions) of uranyl complexes. The mutual packing of the chains to form a three-dimensional framework is determined by a system of hydrogen bonds involving oxygen atoms of the uranyl ions and carboxyl groups and nitrogen atoms of isonicotinic acid molecules with a zwitterionic structure.
