Cover illustration: A view of the unit cell of bis(tetraethylammonium) di--chloro-bis[dichloropalladium(II)] at 292 K along the c axis. Displacement ellipsoids are drawn at the 50% probability level and H atoms are shown as small spheres of arbitrary radii. See Fábry, Dusek, Fejfarová, Krupková, Vanek & Nemec [Acta Cryst. (2004), C60, m426-m430].
KSc(HAsO4)2 and RbScAs2O7 are both characterized by three-dimensional octahedral–tetrahedral frameworks, with intersecting tunnels hosting the alkali atoms. KSc(HAsO4)2 represents a new structure type, while RbScAs2O7 is the first reported diarsenate isotypic with KAlP2O7.
The triclinic (α) and monoclinic (β) modifications of CsSc(HAsO4)2 have three-dimensional octahedral–tetrahedral framework structures, with tunnels hosting the Cs atoms, and represent the first arsenate examples of their structure types. Strong to weak hydrogen bonds reinforce both frameworks.
The crystal structure of the new chromate Ce(CrO4)4·2H2O, prepared from an acidic aqueous solution at room temperature, is built from isolated CrO4 tetrahedra connected to isolated Ce(O,H2O)n (n = 8 and 9) polyhedra.
The peroskite oxynitride SrNbO2N crystallizes in space group , both at room temperature and at 1.5 K. The Nb(O,N)6 octahedra are slightly rotated with respect to the tetragonal axis. A partially order of oxygen and nitrogen on the anionic sites was found.
Hydrothermally synthesized Mg7(AsO4)2(HAsO4)4 has a framework structure built of edge- and corner-sharing MgO6, MgO4(OH)2, MgO5, AsO3(OH) and AsO4 polyhedra. The compound contains a very short hydrogen bond [O⋯O = 2.468 (3) Å].