Hydrothermal Synthesis, Crystal Structure, Solid-State NMR Spectroscopy, and Ionic Conductivity of Na5InSi4O12, a Silicate Containing a Single 12-Membered Ring

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• 作者：Ling-I Hung ; Sue-Lein Wang ; Sung-Ping Szu ; Chan-Yen Hsieh ; Hsien-Ming Kao ; and Kwang-Hwa Lii
• 刊名：Chemistry of Materials
• 出版年：2004
• 出版时间：May 4, 2004
• 年：2004
• 卷：16
• 期：9
• 页码：1660 - 1666
• 全文大小：276K
• 年卷期：v.16,no.9(May 4, 2004)
• ISSN：1520-5002

文摘

Na₅InSi₄O₁₂ has been synthesized by a high-temperature, high-pressure hydrothermalmethod and characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. It is isotypic to Na₅ScSi₄O₁₂. The structure consists of 12-membered single rings ofcorner-sharing SiO₄ tetrahedra linked together via corner sharing by single InO₆ octahedrato form a 3-D framework that delimits two types of channels along the c-axis. There are sixindependent sodium sites. The Na atoms within the 12-ring channels are immobile and theNa atoms within 7-ring channels are highly mobile. The ²⁹Si MAS NMR exhibits one Q³and one Q⁴ resonance, each of which is split into two peaks because of inequivalent chemicalenvironments caused by partially occupied Na sites in the 7-ring channels. Na ionconductivity measurements on a pressed pellet of the title compound were performed. TheArrhenius plot of dc conductivity shows a change in slope near 220 C. We attribute this tothe activation of the Na site that is situated between 7-ring channels and may serve as aconnecting link between the channels. Crystal data: trigonal, space group R-3c (No. 167), a= 21.7158(9) Å, c = 12.4479(7) Å, and Z = 18.