Aromatic hexazine [N6]4- anion featured in the complex structure of the high-pressure potassium nitrogen compound K9N56
Aromatic hexazine [N6]4- anion featured in the complex structure of the high-pressure potassium nitrogen compound K9N56
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DOI：
10.1038/s41557-023-01148-7
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发表时间：
2023-03-06
期刊：
影响因子：
21.8
通讯作者：
Dubrovinskaia, Natalia
中科院分区：
文献类型：
--
作者：
Laniel, Dominique;Trybel, Florian;Dubrovinskaia, Natalia
最近的高压合成五唑酸盐和随后的芳香[N-5]（-）阴离子在大气压下的稳定已经对氮化学产生了巨大的影响。其他芳香氮也被积极寻找，包括六氮苯N-6环。尽管基于从头计算已经提出了各种构型和几何形状，但其中一个很可能的候选是芳香己嗪阴离子[N-6]（4-）。在激光加热的金刚石砧细胞中，氮气和KN3在高压（46和61 GPa）和高温（估计超过2000 K）下直接反应形成了高压钾氮化合物K9N56。利用同步加速器x -射线单晶衍射分析了k9n56的复杂结构（每胞520个原子），并用密度泛函理论计算证实了其结构。所观察到的己嗪阴离子[N-6]（4-）是平面的，被认为是芳香的。
The recent high-pressure synthesis of pentazolates and the subsequent stabilization of the aromatic [N-5](-) anion at atmospheric pressure have had an immense impact on nitrogen chemistry. Other aromatic nitrogen species have also been actively sought, including the hexaazabenzene N-6 ring. Although a variety of configurations and geometries have been proposed based on ab initio calculations, one that stands out as a likely candidate is the aromatic hexazine anion [N-6](4-). Here we present the synthesis of this species, realized in the high-pressure potassium nitrogen compound K9N56 formed at high pressures (46 and 61 GPa) and high temperature (estimated to be above 2,000 K) by direct reaction between nitrogen and KN3 in a laser-heated diamond anvil cell. The complex structure of K9N56-composed of 520 atoms per unit cell-was solved based on synchrotron single-crystal X-ray diffraction and corroborated by density functional theory calculations. The observed hexazine anion [N-6](4-) is planar and proposed to be aromatic.