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• 作者：Matthew D. Ward ; Adel Mesbah ; Stefan G. Minasian ; David K. Shuh ; Tolek Tyliszczak ; Minseong Lee ; Eun Sang Choi ; S茅bastien Leb猫gue ; James A. Ibers
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：July 7, 2014
• 年：2014
• 卷：53
• 期：13
• 页码：6920-6927
• 全文大小：400K
• ISSN：1520-510X

文摘

The solid-state MU₈Q₁₇ compounds ScU₈S₁₇, CoU₈S₁₇, NiU₈S₁₇, TiU₈Se₁₇, VU₈Se₁₇, CrU₈Se₁₇, CoU₈Se₁₇, and NiU₈Se₁₇ were synthesized from the reactions of the elements at 1173 or 1123 K. These isostructural compounds crystallize in space group C_2h³ - C2/m of the monoclinic system in the CrU₈S₁₇ structure type. X-ray absorption near-edge structure spectroscopic studies of ScU₈S₁₇ indicate that it contains Sc³⁺, and hence charge balance is achieved with a composition that includes U³⁺ as well as U⁴⁺. The other compounds charge balance with M²⁺ and U⁴⁺. Magnetic susceptibility measurements on ScU₈S₁₇ indicate antiferromagnetic couplings and a highly reduced effective magnetic moment. Ab Initio calculations find the compound to be metallic. Surprisingly, the Sc鈥揝 distances are actually longer than all the other M鈥揝 interactions, even though the ionic radii of Sc³⁺, low-spin Cr²⁺, and Ni²⁺ are similar.