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| Quantum Chemical Study on the Interactions of NO(3) with RDX and Four Decomposition Intermediates |
| 作者: Zhang, JD(Zhang, Jidong)1,2; Cheng, XL (Cheng, Xinlu)1; Zhao, F(Zhao, Feng)3 |
| 来源出版物: PROPELLANTS EXPLOSIVES PYROTECHNICS 卷: 35 期: 4 页: 315-320 DOI: 10.1002/prep.200900102 出版年: AUG 2010 |
| 被引频次: 0 (来自 Web of Science) |
引用的参考文献: 26 [ 查看 Related Records ]  引证关系图 |
| 摘要: Recently NO(3) (nitrate radical) was predicted to he formed during the decomposition of RDX However. experimental studies of the gaseous products have never detected it In order to verify the prediction, we studied the interactions of NO(3) with RDX and four RDX decomposition intermediates (RI) R. C(3)H(5)N(5)O(4). OST. and TAZ) by using density functional theory (I)FT) It is found that NO, radical can he converted into NO(2) during the process of interactions with the above-mentioned five molecules In other words. NO, radical can be consumed in these processes. which gives an explanation for the disappearance of NO3 Transition state theory (TST) calculations lead to the same results The binding energies are calculated to estimate the strength of interactions The energy of NO(3) with RDR is the largest. which indicates this process is most likely to occur Our calculation provides a support to the prediction of the format ton of NO(3) |
| Mathematical modelling of the decomposition of explosives |
| 作者: Smirnov, LP (Smirnov, L. P.) |
| 来源出版物: RUSSIAN CHEMICAL REVIEWS 卷: 79 期: 5 页: 421-437 DOI: 10.1070/RC2010v079n05ABEH004133 出版年: 2010 |
| 被引频次: 0 (来自 Web of Science) |
| 引用的参考文献: 169 [ 查看 Related Records ] 引证关系图 |
| 摘要: Studies on mathematical modelling of the molecular and supramolecular structures of explosives and the elementary steps and overall processes of their decomposition are analyzed. Investigations on the modelling of combustion and detonation taking into account the decomposition of explosives are also considered. It is shown that solution of problems related to the decomposition kinetics of explosives requires the use of a complex strategy based on the methods and concepts of chemical physics, solid state physics and theoretical chemistry instead of empirical approach. The bibliography includes 168 references. |
| Self-Accelerated Mechanochemistry in Nitroarenes |
| 作者: Kuklja, MM (Kuklja, Maija M.)1; Rashkeev, SN (Rashkeev, Sergey N.)2 |
| 来源出版物: JOURNAL OF PHYSICAL CHEMISTRY LETTERS 卷: 1 期: 1 页: 363-367 DOI: 10.1021/jz9001967 出版年: JAN 2010 |
| 被引频次: 1 (来自 Web of Science) |
| 引用的参考文献: 20 [ 查看 Related Records ] 引证关系图 |
| 摘要: The initiation of explosive decomposition in two energetic crystals, diamino-dinitroethylene (DADNE, C(2)H(4)N(4)O(4)) and triamino-trinitrobenzene (TATB, C(6)H(6)N(6)O(6)), was investigated using density functional theory. The initial chemical reactions in ideal TATB crystals were found to be determined by three main decomposition mechanisms that are almost unaffected by a shear-strain-induced deformation, C-NO(2) homolysis, nitro-nitrite isomerization, and proton transfer. The two latter reactions are nearly isoenergetic and have lower activation, energies than the first reaction. At the same time, decomposition of DADNE is found to depend strongly on the molecular environment; molecules in ideal DADNE crystals favor nitro nitrite isomerization, while molecules located at shear planes decompose via the C-NO(2) homolysis pathway. We also established that the shear-strain accumulated in the-DADNE dashboard-shaped molecular layers triggers an exothermic regime at fairly early stages of decomposition. In contrast, the structure of TATB that consists of flat, graphite-like molecular layers activates accelerated exothermal chemistry only at much higher concentrations of initial decomposition products. |
| Hydroxyl Radical Initiated Oxidation of s-Triazine: Hydrogen Abstraction Is Faster than Hydroxyl Addition |
| 作者: da Silva, G (da Silva, Gabriel)1; Bozzelli, JW (Bozzelli, Joseph W.)2; Asatryan, R(Asatryan, Rubik)2 |
| 来源出版物: JOURNAL OF PHYSICAL CHEMISTRY A 卷: 113 期: 30 页: 8596-8606 DOI: 10.1021/jp904156r 出版年: JUL 30 2009 |
| 被引频次: 8 (来自 Web of Science) |
| 引用的参考文献: 65 [ 查看 Related Records ] 引证关系图 |
| 摘要: Reaction with the hydroxyl radical (HO(center dot)) is the primary removal mechanism for organic compounds in the atmosphere, and an important process in combustion. Molecules with unsaturated carbon sites are thought to react with HO(center dot) via a rapid addition mechanism, with little or no barrier; this results in short lifetimes relative to the saturated alkanes, which undergo slower abstraction reactions. Computational chemistry and reaction rate theory are used in this study to investigate the s-triazine + HO(center dot) reaction. We report that HO(center dot) addition at a carbon ring site proceeds with the largest known barrier for addition to an unsaturated carbon (9.8 kcal mol(-1) at the G3X level of theory). Abstraction of a hydrogen atom in s-triazine by HO(center dot), forming the s-triazinyl radical + H(2)O, proceeds with a barrier of only 3.3 kcal mol(-1), and this process dominates over HO(center dot) addition. Our results are in contrast to those for the analogous reactions in benzene, where the abstraction reaction to phenyl + H(2)O is slower than the HO(center dot) addition, which forms a radical adduct that can further react with O(2) or dissociate to phenol + H(center dot). The lifetime of s-triazine toward the hydroxyl radical in the troposphere is estimated at 6.4 years, potentially making it a long-lived pollutant. The aromatic s-triazine (1,3,5-triazine) molecule is a structural feature in herbicides such as atrazine and is a decomposition product of the common energetic material cyclotrimethylenetrinitramine (RDX). While the abstraction reaction dominates for the parent s-triazine, the addition mechanism may be of importance in the atmospheric degradation of substituted triazines, like atrazine, where ring H atoms are not available for abstraction. The high-barrier addition mechanism forms an activated hydroxy-triazinyl adduct which predominantly dissociates to 2-hydroxy-1,3,5-triazine (OST) + H(center dot). This OST species is a known intermediate of RDX decomposition. Results are also presented for isomerization of the less-stable 1,3,5-triazine-N-oxide OST species (which may form via unimolecular pathways in the liquid-phase decomposition of RDX) to 2-hydroxy-1,3,5-triazine. A reaction mechanism is proposed for further oxidation of the s-triazinyl radical, where an OST isomer is also a potential product. |
| Unimolecular Decomposition of 5-Aminotetrazole and its Tautomer 5-Iminotetrazole: New Insight from Isopotential Searching |
| 作者: Paul, KW (Paul, Kristian W.)2; Hurley, MM(Hurley, Margaret M.)2; Irikura, KK (Irikura, Karl K.)1 |
| 来源出版物: JOURNAL OF PHYSICAL CHEMISTRY A 卷: 113 期: 11 页: 2483-2490 DOI: 10.1021/jp810359t 出版年: MAR 19 2009 |
| 被引频次: 7 (来自 Web of Science) |
| 引用的参考文献: 35 [ 查看 Related Records ] 引证关系图 |
| 摘要: Aminotetrazole compounds have become attractive ingredients in gas generating compositions, solid rocket propellants, and green pyrotechnics. Therefore, a fundamental understanding of their thermal decomposition mechanisms and thermodynamics is of great interest. In this study, the specular reflection isopotential searching method was used to investigate the unimolecular decomposition mechanisms of 5-iminotetrazole (5-ITZ), 1H-5-aminotetrazole (1H-5-ATZ), and 2H-5-aminotetrazole (2H-5-ATZ). Subsequent thermochemical analysis of the unimolecular decomposition pathways was performed at the CCSD(T)/aug-cc-pVTZ//B3LYP/6-311++G(3df,3pd) level of theory. Based upon the relative reaction barriers predicted in this study, the initial gaseous products of 5-ITZ unimolecular decomposition are HN(3),, and NH(2)CN (calculated activation barrier equal to 199.5 kJ/mol). On the other hand, the initial gaseous products of 1H-5-ATZ and 2H-5-ATZ unimolecular decomposition are predicted to be N(2) and metastable CH(3)N(3) (calculated activation barriers equal to 169.2 and 153.7 kJ/mol, respectively). These predicted unimolecular decomposition products and activation barriers are in excellent agreement with thermal decomposition experiments performed by Lesnikovich et al. [Lesnikovich, A.I., Ivashkevich, O. A.; Levchik, S. V.; Balabanovich, A. I.; Gaponik, P. N.; Kulak, A. A. Thermochim, Acta 2002, 388, 233], in which the apparent activation barriers were measured to be approximately 200 and 150 kJ/mol, respectively, for 5-ITZ and 1H-5-ATZ/2H-5-ATZ. |
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