The variety of microporous polyhedral framework solids has increased severely in the last years.[1] The largest classes of microporous materials are still aluminosilicates (Al-O-Si) and aluminophosphates (Al-O-P) as well as their isomorphic substituted forms. These compounds have been studied extensively because of their interesting properties and applications in industrial processes as, for instance, catalysts and ion-exchange materials. A promising strategy for the synthesis of new open-framework materials with elements others than Al or Si is to connect larger building units like clusters in vanadates and molybdates or secondary building units (SBUs) in large-pore indium sulfides. [2][3][4][5][6][7] The interconnection of polyoxometal building blocks like polyoxovanadates by means of covalent bonds could create new porous materials with ultralow framework densities and high porosity. The catalytic or photochemical reactivity of such transition-metal-based materials could be enhanced relative to that of Si-or Al-containing materials. Vanadium is of particular interest because it shows a flexible coordination behavior as well as a great variety of valence states. VO 4 tetrahedra, VO 5 square pyramids, and VO 6 octahedra are often observed as primary building units in polyoxovandate compounds.[8] These building units are able to form larger aggregates and/or clusters by condensation of the polyhedra. The clusters or aggregates may then be joined through metal coordination complexes to create three-dimensional framework structures. During the last years a number of pure and mixed vanadates like vanadiumborates, -arsenates, -germanates, and -phosphates with organic and inorganic counterions have been prepared. [9][10][11][12][13][14] In our investigations we attempted to incorporate sulfur and germanium in anionic vanadium clusters in order to enhance the structural diversity of the building units and to generate possible porous compounds. Here we report the synthesis and characterization of the two new mixed Ge/V polyoxothio compounds (dien-H 3 )

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GeO3S‐Tetraeder und quadratisch‐pyramidale VO5‐Einheiten sind die primären Baueinheiten von zwei neuen Verbindungen, die das ungewöhnliche Anion [V14Ge8O42S8]12− enthalten (siehe Ausschnitt aus der Struktur; Ge schwarz, O rot, S gelb, V grau). Beide Verbindungen wurden unter Solvothermalbedingungen synthetisiert. Starke antiferromagnetische Austauschwechselwirkungen zwischen den V4+‐Zentren bestimmen die magnetischen Eigenschaften.

Two new silver solid electrolytes, Ag 4 I 2 SeO 4 and Ag 3 ITeO 4 , have been synthesized by solid state reactions starting from stoichiometric mixtures of Ag 2 O and AgI with SeO 2 , or TeO 2 , respectively, at elevated oxygen pressures. The new materials have been characterized using powder X-ray diffraction, differential scanning calorimetry, ionic conductivity measurements and single crystal structure determination. Both compounds, Ag 4 I 2 SeO 4 and Ag 3 ITeO 4 , show an abrupt increase in the ionic conductivity in the temperature range of 50 to 70°C and 90 to 130°C, respectively. Ag 4 I 2 SeO 4 has a silver ion conductivity of 1.6 ϫ 10 Ϫ3 at 30°C with an activation energy of 0.22 eV, between 30 and 51°C. It crystallizes as green crystals in Pna2 1 with a ϭ 9.3514 (1) Å , b ϭ 1071 13.1552(4) Å , c ϭ 7.0886(4) Å , V ϭ 871.80(6) Å 3 and Z ϭ 4. The crystal structure consists of isolated SeO 4 tetrahedra separated by Ag ϩ and I Ϫ ions. Ag 3 ITeO 4 crystallizes in P2 1 /c with a ϭ 19.6597(2) Å , b ϭ 7.1240(4) Å , c ϭ 13.3598(3) Å , β ϭ 97.795(2)°, V ϭ 1853.83(11) Å 3 and Z ϭ 12. The structure consists of 1 ϱ [TeO 4/2 O 2/1 ] 2Ϫ isopolyanions, extending along the b-axis. The chains are separated by Ag ϩ and I Ϫ ions. Ag 3 ITeO 4 has a silver ion conductivity of 7.4 ϫ 10 Ϫ5 Ω Ϫ1 cm Ϫ1 at 30°C, with an activation energy of 0.27 eV between 25 and 100°C.

Single crystals of AgVSeO 5 and AgVTeO 5 were obtained under hydrothermal conditions at 190°C by reacting stoichiometric amounts of AgNO 3 , NaVO 3 , TeO 2 and SeO 2 , respectively. AgVSeO 5 crystallizes in Pbcm with a ϭ 418.14(3) pm, b ϭ 2007.70(6) pm, c ϭ 521.17(2) pm, V ϭ 437.52(2) ϫ 10 6 pm 3 and Z ϭ 4, as red needles. The structure consists of VO 5 square pyramids, trigonal SeO 3 pyramids and AgO 8 polyhedra, as primary building units. The VO 5 square pyramids are linked to chains running along the c-axis, by sharing oxygen atoms in the basal plane in cisposition. The remaining basal O atoms of the VO 5 moieties are shared with two oxygen atoms of the SeO 3 units. The resulting polyanionic strands of composition [VSeO 5 ] Ϫ are interconnected by silver atoms to form a three dimensional network. AgVTeO 5 crystallizes as yellow needles in P2 1 /c with a ϭ 586.59(1) pm, b ϭ