Synthesis, Structural Characterization and Chemical Bonding of Sr 7 Li 6 Sn 12 and its Quaternary Derivatives with Eu and Alkaline Earth Metal (Mg, Ca, Ba) Substitutions. A Tale of Seven Li-Containing Stannides and Two Complex Crystal Structures: Synthesi
Synthesis, Structural Characterization and Chemical Bonding of Sr 7 Li 6 Sn 12 and its Quaternary Derivatives with Eu and Alkaline Earth Metal (Mg, Ca, Ba) Substitutions. A Tale of Seven Li-Containing Stannides and Two Complex Crystal Structures: Synthesi
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Sr 7 Li 6 Sn 12 及其四元衍生物与Eu和碱土金属（Mg、Ca、Ba）取代物的合成、结构表征和化学键合。
DOI：
10.1002/ejic.202000179
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发表时间：
2020
影响因子：
2.3
通讯作者：
Bobev, Svilen
中科院分区：
文献类型：
--
作者：
Osman, Hussien H.;Bobev, Svilen
本文讨论了以碱土金属（Ca, Mg, Ba）和稀土金属Eu取代的新型三元化合物sr7li6sn12及其六个季系衍生物的合成和结构表征，得到单斜或正交对称的晶相。标题化合物是通过相应元素的高温固相反应合成的。晶体结构用单晶X射线衍射法测定。（Sr,Ca） 7li6sn12和Eu7(Mg,Li) 6sn12相是一种新的结构类型（空间群pp2 /m， No. 10），而sr7li6sn12和其余标题相是在正交基心空间群pcmmm （No. 10）中结晶的。65)，类似于Eu7Li8-xSn10 +x（x≈2.0）相，具有ce7li8ge10结构类型（Pearson codeoC50）。对所得结构的仔细检查表明，Li和Sn原子之间复杂的无序，这是由价电子的总数决定的。对实验结果的讨论也得到了DFT电子结构计算的支持。
In this paper, we discuss the synthesis and the structural characterization of the new ternary compound Sr7Li6Sn12and its six quaternary derivatives, where alkaline earth metals (Ca, Mg, Ba) and the rare earth metal Eu are substituted, yielding crystalline phases of monoclinic or orthorhombic symmetry. The title compounds were synthesized via high‐temperature solid‐state reactions of the corresponding elements. The crystal structures were determined by single‐crystal X‐ray diffraction methods. The (Sr,Ca)7Li6Sn12and Eu7(Mg,Li)6Sn12phases represent a new structure type (space groupP2/m, No. 10) while Sr7Li6Sn12and the rest of the title phases crystallize in the orthorhombic base‐centered space groupCmmm(No. 65) which is similar to the Eu7Li8–xSn10+x(x≈ 2.0) phase with the Ce7Li8Ge10structure type (Pearson codeoC50). Careful examination of the resulting structures shows intricate disordering between Li and Sn atoms, which is governed by the total number of valence electrons. The discussion of experimental results is also supported by DFT electronic structure calculations.