The pressure-induced phase transition and polymerization of nitrogen-rich molecules are widely focused on due to their extreme importance for the development of green high-energy-density materials. Here, we present a study of the phase-transition behaviour and chemical reaction of 1H-tetrazole up to 100 GPa using in situ Raman, IR, X-ray diffraction, neutron diffraction techniques and theoretical calculations. A phase transition above 2.6 GPa was identified and the high-pressure structure was determined with one molecule in a unit cell instead of two molecules as reported before. The 1H-tetrazole polymerized reversibly below 100 GPa, probably through carbon–nitrogen bonding instead of nitrogen–nitrogen bonding. Our studies update the structure model of the high-pressure phase of 1H-tetrazole, and present the possible intermolecular bonding route for the first time, which gives new insights to understand the phase transition and chemical reaction of nitrogen-rich compounds, and is of benefit for designing new high-energy-density materials.

中文翻译：

---

1H-四唑在高达 100 GPa 的高压下的相变和化学反应性

富氮分子的压力诱导相变和聚合因其对绿色高能量密度材料的开发极其重要而受到广泛关注。在这里，我们研究了 1H-四唑在高达 100 GPa 的压力下使用原位的相变行为和化学反应拉曼、红外、X 射线衍射、中子衍射技术和理论计算。确定了高于 2.6 GPa 的相变，并且高压结构是用一个晶胞中的一个分子来确定的，而不是之前报道的两个分子。1H-四唑在 100 GPa 以下可逆聚合，可能是通过碳氮键而不是氮氮键。我们的研究更新了1H-四唑高压相的结构模型，并首次提出了可能的分子间键合路线，为理解富氮化合物的相变和化学反应提供了新的见解，是有利于设计新的高能量密度材料。