A Soluble Phosphorus-Centered Keggin Polyoxoniobate with Bicapping Vanadyl Groups

作者:Son Jung Ho; Ohlin C Andre; Johnson Rene L; Yu Ping; Casey William H*
来源:Chemistry - A European Journal, 2013, 19(16): 5191-5197.
DOI:10.1002/chem.201204563

摘要

A water-soluble tetramethylammonium (TMA) salt of a novel Keggin-type polyoxoniobate has been isolated as TMA9[PV2Nb12O42]19H2O (1). This species contains a central phosphorus site and two capping vanadyl sites. Previously only a single example of a phosphorus-containing polyoxoniobate, [(PO2)3PNb9O34]15, was known, which is a lacunary Keggin ion decorated with three PO2 units. However, that cluster was isolated as an insoluble structure consisting of chains linked by sodium counterions. In contrast, the [PV2Nb12O42]9 cluster in 1 is stable over a wide pH range, as evident by 31P and 51V NMR, UV/Vis spectroscopy, and ESI-MS spectrometry. The ease of substitution of phosphate into the central tetrahedral position suggests that other oxoanions can be similarly substituted, promising a richer set of structures in this class.

  • 出版日期2013-4