CRYSTAL AND MOLECULAR-STRUCTURE OF NEPTUNYL MALONATE TETRAHYDRATE (NPO2)2C3H2O4.4H2O

The single-crystal x-ray structure is solved for (NPO2)2C3H2O4-4H2O (1 ) (Siemens P3/PC, graphite monochromator, Mo Kalpha-radiation). The mo noclinic cell constants are a = 8.840(1), b = 15.535(2), c = 9.069(2) angstrom, beta = 1.14.43(2)-degrees, Z = 4, space group P2(1)/n, d(cal c) = 4.16 g/cm3, 2030 reflections with I > 3sigma(I), R = 0. 036, and R(w) = 0. 040. The crystal structure of I is constructed of NpO2+, C3H 2O42-, coordinated water, and waters of crystallization. The two cryst allographically unique NpO2 groups (Np coordination number 7, pentagon al bipyramidal coordination polyhedron) are joined into a system of '' half-square' cationic networks in which one group acts as a monodentat e ligand and the other is bidentate. The malonate ion additionally joi ns Np atoms of one network and neighboring networks that are not bonde d to each other by cation - cation interactions.