Laniel D, Weck G, Gaiffe G, Garbarino G, Loubeyre P
CEA, DAM, DIF , F-91297 Arpajon , France.
European Synchrotron Radiation Facility , 6 Rue Jules Horowitz BP220 , F-38043 Grenoble CEDEX, France.
J Phys Chem Lett. 2018 Apr 5;9(7):1600-1604. doi: 10.1021/acs.jpclett.8b00540. Epub 2018 Mar 15.
Polynitrogen compounds have been actively pursued driven by their potential as ultra-high-performing propellants or explosives. Despite remarkable breakthroughs over the past two decades, the two figures of merit for a compelling material, namely a large fraction of nitrogen by weight and a bulk stability under ambient conditions, have not yet been achieved. We report the synthesis of a lithium pentazolate solid by compressing and laser-heating lithium embedded in molecular N around 45 GPa along with its recovery under ambient conditions. The observation by Raman spectroscopy of vibrational modes unique to the cyclo-N anion is the signature of the formation of LiN. Mass spectroscopy experiments confirm the presence of the pentazolate anion in the recovered compound. A monoclinic lattice is obtained from X-ray diffraction measurements and the volume of the LiN compound under pressure is in good agreement with the theoretical calculations.
多氮化合物因其作为超高性能推进剂或炸药的潜力而受到积极研究。尽管在过去二十年中取得了显著突破，但一种有吸引力的材料的两个品质因数，即高重量分数的氮和在环境条件下的整体稳定性，尚未实现。我们报告了通过在约45 GPa的压力下压缩并激光加热嵌入分子氮中的锂来合成五唑锂固体，并在环境条件下对其进行回收。通过拉曼光谱观察到环氮阴离子特有的振动模式是LiN形成的标志。质谱实验证实了回收化合物中存在五唑阴离子。通过X射线衍射测量获得了单斜晶格，并且LiN化合物在压力下的体积与理论计算结果吻合良好。
