Zhang Xueli, Gong Xuedong
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
J Mol Model. 2015 Feb;21(2):26. doi: 10.1007/s00894-015-2581-9. Epub 2015 Jan 29.
5-Nitro-3-trinitromethyl-1H-1,2,4-triazole (NTMT, A) and its substituted derivatives A-CH3, A-OCH3, A-NH2, A-OH, A-NO2, and A-ONO2 were studied using density functional theory (DFT). For all of the molecules except for A-ONO2, the C-NO2 bond in the trinitromethyl group was found to be the weakest, and no transition state occurred during the scission of this bond. The weakest C-NO2 of the trinitromethyl group bond dissociation energies for all of the molecules were all very similar. Most of the title molecules had similar frontier orbital distributions and comparable energy gaps between the frontier orbitals. The impact sensitivity (h 50, in cm), predicted at various levels of theory, decreased in the order A-NH2 (53.0-71.0) > A-CH3 (53.0) > A (36.7) > A-OCH3 (32.6-42.3) > A-OH (26.7-53.0) > A-NO2 (5.6-7.4) > A-ONO2 (4.6-6.1). Their detonation velocities (D), detonation pressures (P), and specific impulses (I s) were 8.02-8.82 km/s, 29.92-35.54 GPa, and 214-260 s, respectively. Composite explosives made from hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and A, A-OH, A-NH2, A-NO2, or A-ONO2 as an oxidizer were found to possess much better detonation performance (D = 9.04-9.29 km/s, P = 37.25-39.26 GPa, and I s = 270-281 s). Thus, introducing -OCH3, -OH, and -NH2 groups into A produced new explosives with acceptable stability and good detonation performance. A-OH and A-NH2 appear to be promising candidates for oxidizers in composite explosives.
采用密度泛函理论（DFT）对5-硝基-3-三硝基甲基-1H-1,2,4-三唑（NTMT，A）及其取代衍生物A-CH3、A-OCH3、A-NH2、A-OH、A-NO2和A-ONO2进行了研究。对于除A-ONO2之外的所有分子，发现三硝基甲基中的C-NO2键是最弱的，并且在该键断裂过程中未出现过渡态。所有分子的三硝基甲基键解离能中最弱的C-NO2都非常相似。大多数标题分子具有相似的前沿轨道分布以及前沿轨道之间相当的能隙。在不同理论水平下预测的撞击感度（h50，单位为厘米）按以下顺序降低：A-NH2（53.0 - 71.0）＞A-CH3（53.0）＞A（36.7）＞A-OCH3（32.6 - 42.3）＞A-OH（26.7 - 53.0）＞A-NO2（5.6 - 7.4）＞A-ONO2（4.6 - 6.1）。它们的爆速（D）、爆压（P）和比冲（Is）分别为8.02 - 8.82千米/秒、29.92 - 35.54吉帕和214 - 260秒。由六氢-1,3,5-三硝基-1,3,5-三嗪（RDX）与A、A-OH、A-NH2、A-NO２或A-ONO2作为氧化剂制成的混合炸药具有更好的爆轰性能（D = 9.04 - 9.29千米/秒，P = 37.25 - 39.26吉帕，Is = 270 - 281秒）。因此，将-OCH3、-OH和-NH2基团引入A中可制得具有可接受稳定性和良好爆轰性能的新型炸药。A-OH和A-NH2似乎是混合炸药中很有前景的氧化剂候选物。
