Synthesis and Crystal and Electronic Structures of the Na2(Sc4Nb2)(Nb6O12)3 Octahedral Niobium Cluster Oxide. Structural Correlations

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• 作者：Sté ; phane Cordier ; Kaplan Kirakci ; Bruno Fontaine ; Jean-Franç ; ois Halet ; Ré ; gis Gautier ; and Christiane Perrin
• 刊名：Inorganic Chemistry
• 出版年：2006
• 出版时间：January 23, 2006
• 年：2006
• 卷：45
• 期：2
• 页码：883 - 893
• 全文大小：662K
• 年卷期：v.45,no.2(January 23, 2006)
• ISSN：1520-510X

文摘

We report here the synthesis and crystal and electronic structures of the Na₂(Sc₄Nb₂)(Nb₆O₁₂)₃ niobium oxidewhose structure is related to that of Ti₂Nb₆O₁₂. It constitutes a new member of the larger A_nBM₆L₁₂(Z) families (A= monovalent cation located in tetrahedral cavities of units, B = monovalent or trivalent cations located in octahedralcavities of units, M = rare earth, Zr, or Nb, Z = interstitial except for M = Nb). The structural relationshipsbetween the A_nBM₆L₁₂(Z) series (M₆Lⁱ₁₂L^a₆ unit-based compounds with a M₆Lⁱ₆L^i-a_6/2L^a-i_6/2 cluster framework) andChevrel Phases (M₆Lⁱ₈L^a₆ unit-based compounds with a M₆Lⁱ₂L^i-a_6/2L^a-i_6/2 cluster framework) are shown in terms ofM₆L₁₈ and M₆L₁₄ unit packing. Despite a topology similar to that encountered in Chevrel Phases, intercalationproperties are not expected in the Nb₆Oⁱ₆O^i-a_6/2O^a-i_6/2 cluster framework-based compounds. Finally, it is shown,from theoretical LMTO calculations, that a semiconducting behavior is expected for a maximum VEC of 14 in theNb₆Oⁱ₆O^i-a_6/2O^a-i_6/2 cluster framework.