Synthesis, Crystal and Electronic Structure of the Sulfido Ferrate Oxide, Cs11[Fe5S8]2[O]
Synthesis, Crystal and Electronic Structure of the Sulfido Ferrate Oxide, Cs11[Fe5S8]2[O]
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DOI：
10.1002/zaac.201400357
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发表时间：
2014-11
期刊：
影响因子：
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通讯作者：
M. Schwarz;C. Röhr
中科院分区：
文献类型：
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作者：
M. Schwarz;C. Röhr
以含有Fe、Cs2 S2和CsO 2的样品为原料，并以Fe 2 O3取代CsO 2作为氧源，在最高温度1170 K下合成了硫代高铁酸盐氧化物Cs 11 [Fe 5S 8]2[O]。在晶体结构中（tetraxide，tI 84，SG I4/mmm，a = 1199.34（2），c = 1411.65（2）pm，Z = 2，R1 = 0.0188），以1：4原子比存在的两种晶体学上不同的铁离子通过S配体四面体配位[d（Fe-S）= 228.8-238.3 pm]。[FeS 4]四面体通过公共边缘连接以形成与化合物如“AlFe 2S 2”（AxFe 2-yS 2，ThCr 2Si 2-型）的致密四面体层密切相关的“多孔”层。在这两种化合物中，层以1/4和3/4的高度z排列在晶胞中。在两者之间散布着碱性抗衡阳离子。在Cs 11 [Fe 5S 8]2[O]中，一个阳离子位点被氧取代，氧仅与Cs阳离子八面体配位[d（O-Cs）= 285-303 pm]。这些孤立的[OCs 6]八面体的尖端指向两个相邻的硫化高铁酸盐层的孔中。应用晶体学群-子群理论，讨论了混合价态标题化合物A[Fe_2S_2]与Fe Ⅱ型高铁酸盐AxFe_（2-y）S_2的模型化合物K_5 [Fe_8 S_（10）]之间的结构关系。后一种模型化合物用于计算的能带结构的比较和讨论的化学键合在一个层状的FeII sulfido高铁酸盐和相关的中间价Fe II/III标题化合物。
The sulfido ferrate oxide Cs11[Fe5S8]2[O] was synthesized at a maximum temperature of 1170 K from samples containing Fe, Cs2S2 and CsO2 as well as by substituting CsO2 as oxygen source with Fe2O3. In the crystal structure (tetragonal, tI84, SG I4/mmm, a = 1199.34(2), c = 1411.65(2) pm, Z = 2, R1 = 0.0188) two crystallographically different iron ions, which are present in a 1:4 atomic ratio, are tetrahedrally coordinated by S ligands [d(Fe–S) = 228.8–238.3 pm]. The [FeS4] tetrahedra are connected by common edges to form “holey” layers closely related to the dense tetrahedra layers of compounds like “AIFe2S2” (AxFe2–yS2, ThCr2Si2-type). In both compounds the layers are arranged in the unit cell at heights z of 1/4 and 3/4. Inbetween the alkali counter cations are interspersed. In Cs11[Fe5S8]2[O], one cation site is replaced by oxygen, which is octahedrally coordinated by Cs cations only [d(O–Cs) = 285–303 pm]. The tips of these isolated [OCs6] octahedra point into the holes of two adjacent sulfido ferrate layers. The structure relation between the aristotype “A[Fe2S2]”, the mixed-valent title compound and “K5[Fe8S10]”, which serves as a model for the FeII ferrates AxFe2–yS2, are discussed applying the crystallographic group-subgroup formalism. The latter model compound is used in a comparison of the calculated band structures and the discussion of the chemical bonding in a layered FeII sulfido ferrate and the related intermediate valent FeII/III title compound.