Unexpected Structural Complexity in Cesium Thorium Molybdates

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• 作者：Bin Xiao ; Jakob Dellen ; Hartmut Schlenz ; Dirk Bosbach ; Evgeny V. Suleimanov ; Evgeny V. Alekseev
• 刊名：Crystal Growth & Design
• 出版年：2014
• 出版时间：May 7, 2014
• 年：2014
• 卷：14
• 期：5
• 页码：2677-2684
• 全文大小：480K
• 年卷期：v.14,no.5(May 7, 2014)
• ISSN：1528-7505

文摘

Three cesium thorium molybdates [Cs₂Th(MoO₄)₃, Cs₂Th₃(MoO₄)₇, and Cs₄Th(MoO₄)₄] were synthesized via the high-temperature solid-state method. Cs₂Th(MoO₄)₃ crystallizes in orthorhombic space group Pnnm, containing [Th(MoO₄)₃]^{2鈥?/sup> chains extending along the [100] direction. Cs₂Th₃(MoO₄)₇ is based on an open framework with channels occupied by Cs+ ions and running parallel through the [100] direction. It is the first case in which thorium atoms coordinate simultaneously in three distinct environments, namely, 7-coordinated pentagonal bipyramid, 8-coordinated square antiprism, and 9-coordinated tricapped trigonal prism. Cs₄Th(MoO₄)₄ is monoclinic, built from [Th(MoO₄)₄]4鈥?/sup> sheets formed by vertex sharing of MoO₄ tetrahedra and ThO₈ antiprisms. The Raman and infrared spectra were recorded, and the vibrations related to internal and external Mo鈥揙 bonds in the MoO₄2鈥?/sup> coordination geometry were discussed.}