An unprecedented vanadoniobate cluster with ‘trans-vanadium’ bicapped Keggin-type {VNb12O40(VO)2}

Abstract

The first organic-inorganic hybrid vanadoniobate cluster compounds with a bicapped Keggin-type {VNb(12)O(40)(VO)(2)} core have been synthesized and characterized.

Two Members of the {X4Nb16O56} Family (X = Ge, Si) Based on [(GeOH)2Ge2Nb16H2O54]12– and [K(GeOH)2Ge2Nb16H3O54]10–

“…[19] In 1972, Choisnet et al reported the Ge/Nb compound RbNb(GeO 3 ) 3 , the first example of germanium introduced into a niobate. [20] 16 O 56 } family (X = Ge, Si). Large single crystals of these compounds have been successfully synthesized in high yield and characterized by elemental analysis, powder XRD (PXRD), IR spectroscopy, diffuse reflection spectroscopy, single-crystal XRD, and thermogravimetric analyses.…”

A hexaniobate expanded by six [Hg(cyclam)]2+ complexes via Hg–O bonds yields a positively charged polyoxoniobate cluster

“…Polyoxoniobates (PONbs) are a sub-class of POMs featuring mainly the Lindqvist {Nb 6 O 19 } [12][13][14][15] or Keggin clusters {XNb 12 O 40 } (X = Si, Ge) [16][17][18][19] [12,20] as precursors large PONb clusters were prepared, like, e.g. {Nb 12 O 40 } [21,22], {Nb 16 O 56 } [23], {Nb 18 O 54 } [19,24], {Nb 24 O 72 } [25,26], {Nb 27 O 76 } [27], {Nb 31 (Table S1; Supporting information available online). The bond valence sum analysis confirms an oxidation state 5+ with values between 5.01 and 5.09 (average: 5.06) for the niobium atom (Table S2).…”

An unprecedented organic–inorganic hybrid based on the first {Nb10V4O40(OH)2}12−clusters and copper cations

“…11 These reported polyoxoniobates may assist toward the fundamental understanding of chemistry and are expected to find potential application in catalysis.…”