德国李比希吉森大学Schreiner, Peter R.团队近日研究了中性氮同素异形体C_2h-N₆的制备。该成果于2025年6月11日发表在《自然》杂志上。

仅由氮元素组成的化合物（多氮或氮同素异形体）被认为是有前途的清洁储能材料，因为它们的能量含量远高于常见的氢、氨或肼，而且它们在分解时只释放无害的氮。然而，它们的极端不稳定性给合成带来了巨大的挑战，除了N₂之外，没有分离出中性分子氮同素异形体。

研究组介绍了通过氯或溴与叠氮化银的气相反应在室温下制备分子N₆（六氮），然后在10K下将其捕获在氩气基质中。他们还在液氮温度（77 K）下制备了纯N₆薄膜，进一步表明了其稳定性。红外和紫外-可见（UV-Vis）光谱、¹⁵N同位素标记和从头计算有力地支持了该发现。制备N₂以外的亚稳态分子氮同素异形体有助于人们增加基础科学知识，并可能为未来的储能概念开辟新的机会。

附：英文原文

Title: Preparation of a neutral nitrogen allotrope hexanitrogen C2h-N6

Author: Qian, Weiyu, Mardyukov, Artur, Schreiner, Peter R.

Issue&Volume: 2025-06-11

Abstract: Compounds consisting only of the element nitrogen (polynitrogens or nitrogen allotropes) are considered promising clean energy-storage materials owing to their immense energy content that is much higher than hydrogen, ammonia or hydrazine, which are in common use, and because they release only harmless nitrogen on decomposition1. However, their extreme instability poses a substantial synthetic challenge and no neutral molecular nitrogen allotrope beyond N2 has been isolated2,3. Here we present the room-temperature preparation of molecular N6 (hexanitrogen) through the gas-phase reaction of chlorine or bromine with silver azide, followed by trapping in argon matrices at 10K. We also prepared neat N6 as a film at liquid nitrogen temperature (77K), further indicating its stability. Infrared and ultraviolet–visible (UV-Vis) spectroscopy, 15N-isotope labelling and ab initio computations firmly support our findings. The preparation of a metastable molecular nitrogen allotrope beyond N2 contributes to our fundamental scientific knowledge and possibly opens new opportunities for future energy-storage concepts.

DOI: 10.1038/s41586-025-09032-9

Source: https://www.nature.com/articles/s41586-025-09032-9