Aluminum‐ and Gallium‐Containing Open‐Dawson Polyoxometalates1. Issue 7 (5th April 2016)

• Record Type: Journal Article
• Authors: Matsunaga, Satoshi; Inoue, Yusuke; Otaki, Takuya; Osada, Hironori; Nomiya, Kenji
• Is Part Of: Zeitschrift für anorganische und allgemeine Chemie. Volume 642:Issue 7(2016)
• Page Start: 539
• Page End: 545
• Publication Date: 2016-04-05
• Subjects: Polyoxometalates -- Open‐Dawson structural POM -- Aluminum -- Gallium; Chemistry, Inorganic -- Periodicals; Chemistry -- Periodicals; 540
• DOI: 10.1002/zaac.201500794
• Languages: English
• ISSNs: 0044-2313

Abstract

Abstract: Al‐ and Ga‐containing open‐Dawson polyoxometalates (POMs), K10 [{Al4 (μ‐OH)6 }{α, α‐Si2 W18 O66 }]· 28.5H2 O (Al4 ‐open ) and K10 [{Ga4 (μ‐OH)6 }(α, α‐Si2 W18 O66 )]· 25H2 O (Ga4 ‐open ) were synthesized by the reaction of trilacunary Keggin POM, [A‐α‐SiW9 O34 ] 10–, with Al(NO3 )3 · 9H2 O or Ga(NO3 )3 · n H2 O, and unequivocally characterized by single‐crystal X‐ray analysis, 29 Si and 183 W NMR, and FT‐IR spectroscopy as well as elemental analysis and TG/DTA. Single‐crystal X‐ray analysis revealed that the { M 4 (μ‐OH)6 } 6+ ( M = Al, Ga) clusters were included in an open pocket of the open‐Dawson polyanion, [α, α‐Si2 W18 O66 ] 16–, which was constituted by the fusion of two trilacunary Keggin POMs via two W–O–W bonds. These two open‐Dawson structural POMs showed clear difference of the bite angles depending on the size of ionic radii. In cases of both compounds, the solution 29 Si and 183 W NMR spectra in D2 O showed only one signal and five signals, respectively. These spectra were consistent with the molecular structures ofAl4 ‐ andGa4 ‐open, suggesting that these polyoxoanions were obtained as single species and maintained their molecular structures in solution. Abstract :