Cs6[Fe2O6] and Rb4[Fe2O5]: New oxoferrates(III) with edge sharing FeO4 tetrahedra
Cs6[Fe2O6] and Rb4[Fe2O5]: New oxoferrates(III) with edge sharing FeO4 tetrahedra
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Cs6[Fe2O6] 和 Rb4[Fe2O5]：具有共享边缘 FeO4 四面体的新型氧铁酸盐 (III)
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
C. Röhr
中科院分区：
文献类型：
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作者：
G. Frisch;C. Röhr
摘要在500和600 °C下，通过Fe_2O_3与碱金属及其超氧化物AO_2的反应，合成了两种新的铁氧酸盐Cs_6 [Fe_2O_6]和Rb_4 [Fe_2O_5]。用单晶X射线衍射法测定了它们的晶体结构。Cs6[Fe 2 O 6]的结构（单斜晶系，P21/c，a = 724.6（2），B = 1212.1（5），c = 767.6（3）pm，β = 105.03（4）°，Z = 2，R1 = 0.0272，K6[Mn 2 O 6]结构型）含有孤立的双核阴离子[O2 FeO 2FeO 2]6-，由两个共边的FeO 4四面体组成，其也从在Klassengleiche超族C2/m中结晶的钾和铷化合物A6[Fe 2 O 6]中已知。在高铁酸铷（III）Rb 4 [Fe 2 O 5]（单斜晶系，C2/c，a = 711.43（14），B = 1750.0（5），c = 725.3（2）pm，β = 104.72（2）°，Z = 4，R1 = 0.0611）中，类似的结构单元通过共同的O顶点连接形成链1∞[O 1/2 OFeO 2FeO 1/2]4-。由于FeO 4四面体的边缘共享，这两种化合物在Cs6[Fe 2 O 6]和Rb 4 [Fe 2 O 5]中分别显示出273.3（2）pm和265.6（3）pm的短Fe-Fe距离。基于（FeIII/Al）阳离子的堆积相似性，可以推导出两种化合物之间的结构关系。讨论了不同反离子对A_6 [Fe_2O_6]和A_4 [Fe_2O_5]相铁氧酸盐单元结构的影响。
Abstract The two new oxoferrates(III) Cs6[Fe2O6] and Rb4[Fe2O5] were synthesized at temperatures of 500 and 600 °C via reaction of Fe2O3 with the elemental alkali metals (A) and their hyperoxides AO2 in the form of dark-red crystals. Their crystal structures have both been determined by single crystal X-ray diffraction. The structure of Cs6[Fe2O6] (monoclinic, P21/c, a = 724.6(2), b = 1212.1(5), c = 767.6(3) pm, β = 105.03(4)°, Z = 2, R1 = 0.0272, K6[Mn2O6] structure type) contains isolated bi nuclear anions [O2FeO2FeO2]6- composed of two edge sharing FeO4 tetrahedra, which are also known from the potassium and rubidium compounds A6[Fe2O6] that crystallize in the klassengleiche super group C2/m. Comparable building blocks are connected via common O vertices to form chains 1∞[O1/2OFeO2FeOO1/2]4– in the rubidium ferrate(III) Rb4[Fe2O5] (monoclinic, C2/c, a = 711.43(14), b = 1750.0(5), c = 725.3(2) pm, β = 104.72(2)°, Z = 4, R1 = 0.0611). As a consequence of the edge sharing of FeO4 tetrahedra, both compounds show short Fe—Fe distances of 273.3(2) pm in Cs6[Fe2O6] and 265.6(3) pm in Rb4[Fe2O5] respectively. Based on similarities in the packing of the (FeIII/AI) cations, a structural relationship between the two compounds can be derived. The influence of the different counterions on the structure of the oxoferrate units in the phases of general composition A6[Fe2O6] and A4[Fe2O5] is discussed.