Na6 TlSb4: synthesis, structure, and bonding. An electron-rich salt with a chain conformation and a Tl-Tl bond length determined by the cation.
Na6 TlSb4: synthesis, structure, and bonding. An electron-rich salt with a chain conformation and a Tl-Tl bond length determined by the cation.
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Na6 TlSb4：合成、结构和键合。
DOI：
10.1021/ic020728b
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发表时间：
2003
影响因子：
4.6
通讯作者：
J. Corbett
中科院分区：
文献类型：
--
作者：
Bin Li;L. Chi;J. Corbett
标题化合物形成的熔化和退火的化学计量的混合物的元素。通过单晶X-射线衍射方法在单斜空间群C2/c中确定结构，其中a = 15.154（3）A，B = 10.401（2）A，c = 17.413（4）A，和β = 113.57（3）度，Z = 8。通过Sb 2桥对互连的四元Tl-Sb 1-Sb 4-Sb 3环产生摆动状重复单元[Tl（2）Sb（8）]，其通过外部Tl-Tl键进一步互连以形成无限一维链。阳离子在结构中起主要作用。与具有类似摆动状[Tl（4）Sb（6）]重复单元和Tl-Tl互连的Zintl相K（6）Tl（2）Sb（3）相比，Na（6）TlSb（4）具有比预期更紧凑的链构象和明显更小的晶胞体积。根据经验电子计数，EHTB带计算的阴离子，和化合物的测量的双折射率和磁双折射率的新阶段是金属与两个过剩的阳离子。本发明盐中显著较短的T1-T1键（2.954 A）可直接归因于较小的阳离子和跨该键的减少的阳离子间排斥。
The title compound forms on fusion and annealing of a stoichiometric mixture of the elements. The structure was determined by single-crystal X-ray diffraction methods in the monoclinic space group C2/c, with a = 15.154(3) A, b = 10.401(2) A, c = 17.413(4) A, and beta = 113.57(3) degrees, Z = 8. Four-membered Tl-Sb1-Sb4-Sb3 rings interlinked by pairs of Sb2 bridges generate swinglike repeat units [Tl(2)Sb(8)] that are further interlinked through external Tl-Tl bonds to form infinite one-dimensional chains. Cations play a major role in the structure. In contrast to the Zintl-phase K(6)Tl(2)Sb(3) with similar swinglike [Tl(4)Sb(6)] repeating units and Tl-Tl interlinkages, Na(6)TlSb(4) has a more compact conformation of the chains and a notably smaller cell volume than expected. The new phase is metallic with two excess cations according to empirical electron counting, EHTB band calculations for the anion, and the compound's measured resistivities and magnetic susceptibilities. The notably shorter Tl-Tl bond in the present salt (2.954 A) can be directly attributed to the smaller cation and reduced intercation repulsions across that bond.