Cover illustration: The intermolecular organization in a single layered porphyrin array in 5,10,15,20-tetrakis(5,5-dimethyl-1,3,2-dioxaborinan-2-yl)porphyrin nitrobenzene disolvate projected down the b axis of the crystal. Note the large interporphyrin voids within such an assembly. The nitrobenzene solvent molecules and the H atoms have been omitted. See Muniappan, Lipstman & Goldberg [Acta Cryst. (2008), C64, o177-o179].
The crystal structure of a synthetic aenigmatite-type Na–Mn germanate has been determined and compared with the structures of other naturally occurring and synthetic members of the aenigmatite mineral group.
The structure of the title compound consists of silicate double layers separated by [V2O8]8− dimers with Rb+ cations interleaved. It is the first example of an anhydrous diphyllosilicate containing vanadium(IV).
The title compound is isomorphous with the Sr and Eu analogs. The main structural feature is the occurrence of edge-shared bioctahedral Mo10 clusters, and monocapped and bicapped Mo10 clusters forming, respectively, Mo11 and Mo12 clusters, which co-exist randomly in the structure.