Crystal structure of (C2H7N4O)2[(UO2)2(OH)2(C2O4)(CHO2)]

An X-ray diffraction study of the single crystals of (C2H7N4O)(2)[(UO2)(2)(OH)(2)(C2O4)(CHO2)(2)] was carried out. The compound crystallizes in the triclinic system, space group P (1) over bar, Z = 2, a = 5.5621(8) angstrom, b = 8.1489(10) angstrom, c = 11.8757(16) angstrom, alpha = 88.866(7)degrees, beta = 82.204(6)degrees, gamma = 87.378(6)degrees, V = 532.7(1) angstrom(3), rho(calcd) = 2.988 g/cm(3). The main structural units in the crystal are the [(UO2)(2)(OH)(2)(C2O4)(CHO2)(2)](2-) chains corresponding to the crystal chemical group A(2)M(2)(2) (KM21)-M-02 (A = UO22+ M-2 = OH-, K-02 = C2O24-, M-1=CHO2-) of uranyl complexes. The chains are united into a three-dimensional framework through the electrostatic interaction and hydrogen bonds involving uranyl, oxalate, and hydroxyl groups, formate ions, and 1-carbamoylguanidinium cations.