Carrillo-Cabrera Wilder, Hübner Julia-Maria, Freccero Riccardo, Jung Walter, Baitinger Michael, Grin Juri, Schwarz Ulrich
Max-Planck-Institut für Chemische Physik fester Stoffe, Nöthnitzer Straße 40, 01187 Dresden, Germany.
Earth and Planets Laboratory, Carnegie Institution for Science, Washington, District of Columbia 20015, United States.
J Am Chem Soc. 2024 Sep 11;146(36):24759-24763. doi: 10.1021/jacs.4c08745. Epub 2024 Aug 26.
The compound NaBSi was synthesized under high-pressure, high-temperature conditions at pressures ranging from 6 to 9.5 GPa and temperatures from 1070 to 1270 K before quenching to room temperature followed by slow decompression. The crystal structure was determined from microcrystals using precession-assisted electron diffraction tomography, validated by dynamical refinement and full-profile refinements using optimized coordinates from quantum chemical calculations (space group 3̅, Pearson symbol 30, = 5.0735(1) Å and = 16.0004(7) Å). The atomic arrangement consists of a unique framework formed by electron-precise octahedral closo (B) clusters connected via ethane-like (Si) dumbbells. The Na cations occupy cavities in the hierarchical variation of a Heusler-type framework. The balance (Na)([B])(Si) reveals an electron precise Zintl-Wade phase, which is in line with electronic band structure calculations predicting semiconducting behavior.
化合物NaBSi是在6至9.5 GPa的压力和1070至1270 K的温度下，于高压高温条件下合成的，然后淬火至室温，接着缓慢减压。使用进动辅助电子衍射断层扫描技术从微晶中确定晶体结构，并通过动力学精修和全谱精修进行验证，精修使用量子化学计算得到的优化坐标（空间群3̅，皮尔逊符号30， = 5.0735(1) Å， = 16.0004(7) Å）。原子排列由通过类乙烷（Si）哑铃连接的电子精确八面体封闭（B）簇形成的独特框架组成。Na阳离子占据赫斯勒型框架分层变化中的空洞。(Na)([B])(Si)的平衡揭示了一个电子精确的津特耳-韦德相，这与预测半导体行为的电子能带结构计算结果一致。
