Conjugated Energetic Salts Based on Fused Rings: Insensitive and Highly Dense Materials
Conjugated Energetic Salts Based on Fused Rings: Insensitive and Highly Dense Materials
复制标题
DOI：
10.1021/jacs.8b09519
复制
发表时间：
2018-11-07
影响因子：
15
通讯作者：
Shreeve, Jean'ne M.
中科院分区：
文献类型：
--
作者：
Hu, Lu;Yin, Ping;Shreeve, Jean'ne M.
硝氨基功能化的1，2，4-三唑并[4，3-1][1，2，4，5]-四嗪(1)与分子间氢键(HBS)和层间强的非共价相互作用结合时，例如，二羟基铵3，6-dinitramino-1，2，4-triazolo[4，3-b][1，2，4，5]-tetrazine(2c)的层间距为2.9埃，堆积系数为0.805。对于二羟基铵6，6‘-dinitramino-3，3’-azo-1，2，4-triazolo[4，3-b][1，2，4，5]-tetrazine(3b)，两个稠环通过偶氮基相连，从而扩展了共轭体系，得到了更短的层间距2.7Astrom和更高的堆积系数0.807。这些值似乎是四嗪含能材料所报道的最短的层间距和最高的堆积系数。当堆积系数较大时，这两种材料在293K时的密度分别为1.92g cm(-3)和1.99g cm(-3)。与其前体相比，羟基铵部分作为缓冲链(H-N-O-H)，通过氢键将阴阳离子连接起来，产生更有利的堆积，导致更高的密度和更低的灵敏度。所有的羟胺盐的灵敏度都低于它们的中性前体，如化合物2(3J，5N)和化合物2c(25J，360N)。2c(爆速v(D)=9712m S(-1)，爆轰压力P=43 Gpa)和3b(v(D)=10233 m S(-1)；P=49 Gpa)的爆轰性能超过了目前高爆炸性基准，如octahydro-1，3，5，7-tetranitro-1，3，5，7-tetrazocine(HMX)和六硝基六氮杂异伍兹烷(CL-20)。其中几种新型含能材料的分子结构通过单晶X射线衍射法得到了证实。计算和实验结果表明，采用平面大pi共轭体系的稠环在期望的稳定性和高爆震性能之间取得了折衷，从而提高了未来在含能材料设计中的应用。
Nitroamino-functionalized 1,2,4-triazolo [4,3-1)] [1,2,4,5]-tetrazine (1), when combined with intermolecular hydrogen bonds (HBs) and strong noncovalent interactions between layers, results, for example, in an interlayer distance of 2.9 angstrom for dihydroxylammonium 3,6-dinitramino-1,2,4-triazolo[4,3-b][1,2,4,5]-tetrazine (2c) with a packing coefficient of 0.805. For dihydroxylammonium 6,6'-dinitramino-3,3'-azo-1,2,4-triazolo[4,3-b][1,2,4,5]-tetrazine (3b), two fused rings are linked by an azo group, which expands the conjugated system resulting in an even shorter interlayer distance of 2.7 angstrom and a higher packing coefficient of 0.807. These values appear to be the shortest interlayer distances and the highest packing coefficients reported for tetrazine energetic materials. With high packing coefficients, both possess high densities of 1.92 g cm(-3) and 1.99 g cm(-3) at 293 K, respectively. Compared with its precursor, the hydroxylammonium moiety serves as a buffer chain (H-N-O-H), connecting the anion and cation through hydrogen bonds, giving rise to more favorable stacking, and resulting in higher density and lower sensitivity. The sensitivities of all the hydroxylammonium salts are lower than that of their neutral precursors, such as compound 2 (3 J, > 5 N) and compound 2c (25 J, 360 N). The detonation properties of 2c (detonation velocity v(D) = 9712 m s(-1) and detonation pressure P = 43 GPa) and 3b (v(D) = 10233 m s(-1); P = 49 GPa) exceed those of present high explosive benchmarks, such as octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and hexanitrohexaazaisowurzitane (CL-20). The molecular structures of several of these new energetic materials are confirmed by single-crystal X-ray diffraction measurements. Using calculated and experimental results, the fused ring with a planar large pi-conjugated system results in a compromise between desirable stabilities and high detonation properties, thus enhancing future utilization in the design of energetic materials.