The highest nitrogen-containing binary C-N anion, 5-azido-tetrazolate (CN7−), has attracted significant attention owing to its high-energy content. Due to its relative instability and high sensitivity, it is an ongoing challenge to develop more stable and less sensitive novel materials based on CN7−. Towards this goal, we have stabilized the CN7− anion without compromising its energetic performance by formation of its NH3OH+ salt containing an additional NH2OH molecule, [NH3OH][CN7][NH2OH] (2). It possesses the best detonation performance and the lowest mechanical sensitivity among all known CN7−-based materials. The structure-property relationship was elucidated through a careful investigation of the noncovalent interactions in the crystal lattice and the important role of the NH2OH moiety. In addition, the structurally related compound [NH3OH][CN7] (1) was also studied.
具有最高氮含量的二元C-N阴离子, 叠氮四唑离子—CN7−, 因其极高的能量密度受到广泛关注, 但由于CN7−的不稳定性, 以此合成新型低感的高能量密度材料存在极大难度. 本文制备出一种新型高能加合物[NH3OH][CN7][NH2OH], 该化合物在所有已知的CN7−化合物中表现出最好的爆轰性能与最低的机械感度. 为了探索NH2OH分子对含能化合物性质的影响, 我们合成了另一种含能盐[NH3OH][CN7], 并对其与加合物[NH3OH][CN7][NH2OH]的结构与性能进行了比较. 结果表明NH2OH及其氢键作用对于改善CN7−的热稳定性和机械感度起到了重要作用.
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We gratefully acknowledge the National Natural Science Foundation of China (21771108 and 21805138), and the Natural Science Foundation of Jiangsu Province (BK20191291).
Conflict of interest The authors declare that they have no conflict of interest.
Qi Sun was born in Jiangsu (China) in 1993. He is currently a PhD candidate under the supervision of Prof. Ming Lu at Nanjing University Of Science and Technology (NJUST) and a visiting student in the lab of Prof Muralee Murugesu. His research interest is the synthesis of nitrogen-rich high-energy-density materials.
Qiuhan Lin obtained his BSc in 2008 and PhD in 2013 from Beijing Institute of Technology (BIT), China. His current research interest is the synthesis and crystal engineering of energetic salts.
Muralee Murugesu received his PhD degree from the University of Karlsruhe in 2002. He undertook postdoctoral research at the University of Florida, University of California, Berkeley and the University of California, San Francisco. He is currently a full professor at the University of Ottawa. His research focuses on novel nanoscale materials and highly energetic materials.
Ming Lu obtained his BSc in 1984, MSc in 1989 and PhD in 1999 at NJUST. His current research interest is focused on the synthesis and crystal engineering of energetic materials, pharmaceutical intermediates and green chemistry.
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Sun, Q., Li, X., Bamforth, C. et al. Higher performing and less sensitive CN7−-based high-energy-density material. Sci. China Mater. 63, 1779–1787 (2020). https://doi.org/10.1007/s40843-019-1413-9
- high nitrogen
- binary C-N anion
- hydrogen bonds
- high-energy-density material