Crystal structure of barium bis(nitrilotriacetato)cobaltate(III), Ba3[Co(Nta)2]2 · 10H2O

Abstract

Crystals of Ba3[Co(Nta)2]2 · 10H2O (Nta3− is the ion of nitrilotriacetic acid) are obtained (monoclinic crystal system, a = 17.094(3), b = 13.1873(13), c = 21.490(3) A, β = 98.457(18)°, Z = 4, space group I2/c). The crystal structure of the compound is determined by X-ray diffraction analysis. The crystals consist of the Ba2+ cations, water molecules, and [Co(Nta)2]3− anions in which the donor N and 2O atoms of each Nta3− ion are located at opposite faces of the coordination octahedron. The Co(1, 2) atoms are arranged in the inversion centers. The Ba atoms of the complexes form an intricate three-dimensional framework. One of the two crystallographically nonequivalent complexes binds eight Ba atoms, and another one binds six Ba atoms. The coordination number of the Ba(1) atoms (in the general position) is nine (three O atoms of water molecules and six O atoms of the carboxyl groups of five complexes), and that of the Ba(2) atoms (on the 2 axis) is 6 (two O atoms of water molecules and four O atoms of the carboxyl groups of four complexes).