Thioantimonates containing high oxidation state Sb⁵⁺ have been proven to exhibit excellent performance in the design of new materials such as infrared optical crystals and lithium-ion batteries. However, as described by the “inert pair effect”, the preparation of P-block elements containing high oxidation states in sealed systems has been a challenge. In this study, an aliovalent cation substitution strategy was used to design and synthesize three novel thioantimonates(V), A₄BaSb₂Se₈ (A = Cs, Rb) and Rb₂BaSbS₄Cl (RBSSC), respectively, all of which contain rare [SbS₄] tetrahedral units. The introduction of Ba²⁺ ions leads to the distortion and high-density arrangement of [SbSe₄] units, which is manifested as a significant 3.7 times enhancement of the birefringence compared to that of the parent compound Cs₃SbSe₄ (0.041 → Cs₄BaSb₂Se₈ 0.150@1064 nm). By further introducing highly electronegative halogen atoms, the first antimony-based thiohalide(V) RBSSC was synthesized. Theoretical calculations show that the band gap of RBSSC is up to 3.674 eV, larger than those of all known antimony-based thiohalides(III). This work provides strong evidence that the aliovalent cation substitution strategy is an effective way to find new thioantimonate(V) families, and also indicates that the cation size effect introduced by elemental substitution may lead to surprising performance improvements.

中文翻译：

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简单的同价阳离子取代在稀有的硫代锑酸盐 （V） 家族中诱导强光学各向异性增强


含有高氧化态 Sb⁵⁺ 的硫代锑酸盐已被证明在红外光学晶体和锂离子电池等新材料的设计中表现出优异的性能。然而，正如“惰性对效应”所描述的那样，在密封系统中制备含有高氧化态的 P 嵌段元素一直是一个挑战。在本研究中，采用同构价阳离子取代策略设计合成了三种新型硫代锑酸盐 （V），分别是 A₄BaSb₂Se₈ （A = Cs， Rb） 和 Rb₂BaSbS₄Cl （RBSSC），它们都含有稀有的 [SbS₄] 四面体单元。Ba²⁺ 离子的引入导致 [SbSe₄] 单元的畸变和高密度排列，表现为与母体化合物 Cs₃SbSe₄ （0.041 → Cs₄BaSb₂Se₈ 相比，双折射显着增强了 3.7 倍0.150@1064 纳米）。通过进一步引入高电负性卤素原子，合成了第一个锑基硫卤化物 （V） RBSSC。理论计算表明，RBSSC 的带隙高达 3.674 eV，大于所有已知的锑基硫代卤化物 （III）。 这项工作提供了强有力的证据，证明同构价阳离子取代策略是寻找新的硫代锑酸盐 （V） 家族的有效方法，并且还表明元素取代引入的阳离子大小效应可能会导致令人惊讶的性能改进。