Aluminum- and Gallium-Containing Open-Dawson Polyoxometalates

作者：Matsunaga Satoshi; Inoue Yusuke; Otaki Takuya; Osada Hironori; Nomiya Kenji

来源：Zeitschrift fur Anorganische und Allgemeine Chemie, 2016, 642(7): 539-545.

DOI：10.1002/zaac.201500794

• Polyoxometalates
• Open-Dawson structural POM
• Aluminum
• Gallium

Al- and Ga-containing open-Dawson polyoxometalates (POMs), K-10[{Al-4(mu-OH)(6)}{alpha,alpha-Si2W18O66}]center dot 28.5H(2)O (Al-4-open) and K-10[{Ga-4(mu-OH)(6)}(alpha,alpha-Si2W18O66)]center dot 25H(2)O (Ga-4-open) were synthesized by the reaction of trilacunary Keggin POM, [A-alpha-SiW9O34](10-), with Al(NO3)(3)center dot 9H(2)O or Ga(NO3)(3)center dot nH(2)O, and unequivocally characterized by single-crystal X-ray analysis, Si-29 and W-183 NMR, and FT-IR spectroscopy as well as elemental analysis and TG/DTA. Single-crystal X-ray analysis revealed that the {M-4(mu-OH)(6)}(6+) (M = Al, Ga) clusters were included in an open pocket of the open-Dawson polyanion, [alpha,alpha-Si2W18O66](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 Si-29 and W-183 NMR spectra in D2O showed only one signal and five signals, respectively. These spectra were consistent with the molecular structures of Al-4- and Ga-4-open, suggesting that these polyoxoanions were obtained as single species and maintained their molecular structures in solution.

• 出版日期2016-4