Crystal structure of barium perchlorate anhydrate, Ba(ClO₄)₂, from laboratory X-ray powder data

Abstract

The previously unknown crystal structure of barium perchlorate anhydrate, determined and refined from laboratory X-ray powder diffraction data, represents a new structure type. The title compound was obtained by heating hydrated barium perchlorate [Ba(ClO 4 ) 2 · x H 2 O] at 423 K in vacuo for 6 h. It crystallizes in the orthorhombic space group Fddd . The asymmetric unit contains one Ba (site symmetry 222 on special position 8 a ), one Cl (site symmetry 2 on special position 16 f ) and two O sites (on general positions 32 h ). The structure can be described as a three-dimensional polyhedral network resulting from the corner- and edge-sharing of BaO 12 polyhedra and ClO 4 tetrahedra. Each BaO 12 polyhedron shares corners with eight ClO 4 tetrahedra, and edges with two ClO 4 tetrahedra. Each ClO 4 tetrahedron shares corners with four BaO 12 polyhedra, and an edge with the other BaO 12 polyhedron.