17O Solid-State NMR and First-Principles Calculations of Sodium Trimetaphosphate (Na3P3O9), Tripolyphosphate (Na5P3O10), an

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• 作者：Filipe Vasconcelos ; Sylvain Cristol ; Jean-Francois Paul ; Gré ; gory Tricot ; Jean-Paul Amoureux ; Lionel Montagne ; Francesco Mauri ; Laurent Delevoye
• 刊名：Inorganic Chemistry
• 出版年：2008
• 出版时间：August 18, 2008
• 年：2008
• 卷：47
• 期：16
• 页码：7327-7337
• 全文大小：349K
• 年卷期：v.47,no.16(August 18, 2008)
• ISSN：1520-510X

文摘

The assignment of high-field (18.8 T) ¹⁷O MAS and 3QMAS spectra has been completed by use of first-principles calculations for three crystalline sodium phosphates, Na₃P₃O₉, Na₅P₃O₁₀, and Na₄P₂O₇. In Na₃P₃O₉, the calculated parameters, quadrupolar constant (C_Q), quadrupolar asymmetry (η_Q), and the isotropic chemical shift (δ_cs) correspond to those deduced experimentally, and the calculation is mandatory to achieve a complete assignment. For the sodium tripolyphosphate Na₅P₃O₁₀, the situation is more complex because of the free rotation of the end-chain phosphate groups. The assignment obtained with ab initio calculations can however be confirmed by the ¹⁷O{³¹P} MAS-J-HMQC spectrum. Na₄P₂O₇ ¹⁷O MAS and 3QMAS spectra show a complex pattern in agreement with the computed NMR parameters, which indicate that all of the oxygens exhibit very similar values. These results are related to structural data to better understand the influence of the oxygen environment on the NMR parameters. The findings are used to interpret those results observed on a binary sodium phosphate glass.