The First Framework Solid Composed of Vanadosilicate Clusters

In this Communication, we report the first example of a network structure composed of vanadosilicate clusters. We utilized hydrothermal conditions to synthesize a polyoxovanadogermanate (POVG):  (C₄H₁₄N₂)₄[V₁₄O₄₄(GeOH)₈]·6H₂O. By substituting SiO₂ for GeO₂ in the synthesis, a framework solid, H₄V₁₈O₄₆(SiO)₈C₄H₁₂N₂)₄·(H₂O)] ·4H₂O, is formed in which isostructural vanadosilicate clusters are linked by five-coordinate vanadium with a (VO)O₂N₂ environment. The charge-compensating organic amine, 1,4-diaminobutane, in the POVG is covalently bonded to the linking vanadium polyhedra in the framework solid.