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Chen J, Xu J, Xiao T, Gao Z, Bo M, Gu Z, Ma P, Ma C. The regulation of high-energy insensitive compound 2,6-diamino-3,5-dinitropyrazine-1-oxide by external electric field. J Mol Model 2024; 30:83. [PMID: 38403784 DOI: 10.1007/s00894-024-05885-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 02/20/2024] [Indexed: 02/27/2024]
Abstract
CONTEXT The influence of external electric fields (EEFs) on chemical substances has always been a hot topic in the field of theoretical chemistry research. 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is an energetic material with excellent comprehensive properties and enormous potential for application. This article explores the molecular structure, electronic structure, energy change, frontier molecular orbitals (FMOs) and density of states (DOS), UV-Vis spectra, and infrared spectra of LLM-105 under various electric field conditions. The results indicate that negative EEF can improve the stability of LLM-105, reflected in the initiation of changes in bond length and HOMO-LOMO gap. EEF has a significant impact on the electronic structure of LLM-105. The polarization of the electronic structure brings about a change in total energy, which is reflected in the analysis of energy changes. In addition, the external electric field will cause the frequency of the infrared spectra and the UV-Vis spectra to have different degrees of blue shift. The results of the analysis are helpful to understand the changes of energetic materials under the applied electric field. METHODS Based on the density functional theory (DFT), the structural optimization and energy calculation were carried out by using B3LYP/6-311G(d, p) and B3LYP/def2-TZVPP methods, respectively. After optimization convergence, vibration analysis was performed without imaginary frequencies to obtain stable configurations. Then, the molecular structure, electronic structure, energy changes, molecular orbital and density of states, UV-Vis spectra, and infrared spectra were analyzed.
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Affiliation(s)
- Jun Chen
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Jiani Xu
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Tingting Xiao
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zikai Gao
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Mengjie Bo
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Zhihui Gu
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China
| | - Peng Ma
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China.
| | - Congming Ma
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing, 211816, China.
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Ren FD, Liu YZ, Wang XL, Qiu LL, Meng ZH, Cheng X, Li YX. Strong External Electric Fields Reduce Explosive Sensitivity: A Theoretical Investigation into the Reaction Selectivity in NH2NO2∙∙∙NH3. Molecules 2023; 28:molecules28062586. [PMID: 36985558 PMCID: PMC10058811 DOI: 10.3390/molecules28062586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/04/2023] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
Controlling the selectivity of a detonation initiation reaction of explosive is essential to reduce sensitivity, and it seems impossible to reduce it by strengthening the external electric field. To verify this, the effects of external electric fields on the initiation reactions in NH2NO2∙∙∙NH3, a model system of the nitroamine explosive with alkaline additive, were investigated at the MP2/6-311++G(2d,p) and CCSD(T)/6-311++G(2d,p) levels. The concerted effect in the intermolecular hydrogen exchange is characterized by an index of the imaginary vibrations. Due to the weakened concerted effects by the electric field along the −x-direction opposite to the “reaction axis”, the dominant reaction changes from the intermolecular hydrogen exchange to 1,3-intramolecular hydrogen transference with the increase in the field strengths. Furthermore, the stronger the field strengths, the higher the barrier heights become, indicating the lower sensitivities. Therefore, by increasing the field strength and adjusting the orientation between the field and “reaction axis”, not only can the reaction selectivity be controlled, but the sensitivity can also be reduced, in particular under a super-strong field. Thus, a traditional concept, in which the explosive is dangerous under the super-strong external electric field, is theoretically broken. Compared to the neutral medium, a low sensitivity of the explosive with alkaline can be achieved under the stronger field. Employing atoms in molecules, reduced density gradient, and surface electrostatic potentials, the origin of the reaction selectivity and sensitivity change is revealed. This work provides a new idea for the technical improvement regarding adding the external electric field into the explosive system.
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Affiliation(s)
- Fu-De Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
- Correspondence: ; Tel.: +86-351-392-2117
| | - Ying-Zhe Liu
- State Key Laboratory of Fluorine and Nitrogen Chemicals, Xi’an Modern Chemistry Research Institute, Xi’an 710065, China
| | - Xiao-Lei Wang
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
| | - Li-Li Qiu
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Zi-Hui Meng
- School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Xiang Cheng
- School of Intelligent Engineering, Zhengzhou University of Aeronautics, Zhengzhou 450003, China
| | - Yong-Xiang Li
- School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, China
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Theoretically Revealing the Response of Intermolecular Vibration Energy Transfer and Decomposition Process of the DNTF System to Electric Fields Using Two-Dimensional Infrared Spectra. Int J Mol Sci 2023; 24:ijms24054352. [PMID: 36901784 PMCID: PMC10002173 DOI: 10.3390/ijms24054352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 02/12/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
The external electric field (E-field), which is an important stimulus, can change the decomposition mechanism and sensitivity of energetic materials. As a result, understanding the response of energetic materials to external E-fields is critical for their safe use. Motivated by recent experiments and theories, the two-dimensional infrared (2D IR) spectra of 3,4-bis (3-nitrofurazan-4-yl) furoxan (DNTF), which has a high energy, a low melting point, and comprehensive properties, were theoretically investigated. Cross-peaks were observed in 2D IR spectra under different E-fields, which demonstrated an intermolecular vibration energy transfer; the furazan ring vibration was found to play an important role in the analysis of vibration energy distribution and was extended over several DNTF molecules. Measurements of the non-covalent interactions, with the support of the 2D IR spectra, indicated that there were obvious non-covalent interactions among different DNTF molecules, which resulted from the conjugation of the furoxan ring and the furazan ring; the direction of the E-field also had a significant influence on the strength of the weak interactions. Furthermore, the calculation of the Laplacian bond order, which characterized the C-NO2 bonds as trigger bonds, predicted that the E-fields could change the thermal decomposition process of DNTF while the positive E-field facilitates the breakdown of the C-NO2 in DNTFⅣ molecules. Our work provides new insights into the relationship between the E-field and the intermolecular vibration energy transfer and decomposition mechanism of the DNTF system.
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Regulation of external electric field on sensitivity of ICM energetic materials. J Mol Model 2023; 29:62. [PMID: 36738372 DOI: 10.1007/s00894-023-05452-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/12/2023] [Indexed: 02/05/2023]
Abstract
CONTEXT [2,2'-Bi(1,3,4-oxadiazole)]-5,5'-dinitramide (ICM-101), 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102), and 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide (ICM-103) are excellent China-made explosives, but their performance under external electric fields (EEF) has never been explored, especially sensitivity. To study the induction effect of EEF on it, the chemical reactivity, electron localization function (ELF), spectrum, and other parameters were calculated by density functional theory. The results show that the increasing EEF can weaken the △EHOMO-LUMO (△EHOMO-LUMO = EHOMO-ELUMO) materials, making the stability worse and the sensitivity higher. The proportion of the positive electrostatic surface potential area is also smaller under the increasing EEF, indicating that ICM molecules are becoming more and more unstable. The ELF and localized orbital locator (LOL) decrease with the increase of EEF strength, which suggests that the trigger bond length increases, the EBDE decreases, and the molecular sensitivity increases. When the intensity of EEF increases, the absorption peak of the molecular spectrum gradually redshifts, and even a weak new absorption peak appears, indicating that the color of the material may change. Finally, EEF strength affects electron density, nitro charge, and chemical reactivity parameters. METHODS Gaussian 16 software was used for calculation. The calculation levels are B3LYP/6-311G+ (d, p) and B3LYP/Def2-TZVPP. The optimized structure has a local true minimum energy on the potential energy surface and no imaginary frequency. Multiwfn 3.8 and VMD 1.9.3 were used in this work to analyze the ICM series of energetic material wave functions. The strength range of EEF is 0.000-0.016 a.u., and the increasing gradient is 0.002 a.u.
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Regulation of external electric field on the high-energy polynitrogen compound 1,5-diaminotetrazole-4 N-oxide. J Mol Model 2022; 29:28. [PMID: 36585524 DOI: 10.1007/s00894-022-05423-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/15/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND The external electric field (EEF) tends to have a significant impact on chemicals, especially energetic materials. METHODS Molecular structure, electrostatic potential (ESP), electron density difference, density of states (DOS), and frontier molecular orbitals (FMOs) of 1,5-diaminotetrazole-4N-oxide (SYX-9) are calculated by density functional theory (DFT) at B3LYP/6-311G+(d, p) and M062X/def2-TZVP under external electric field. RESULTS Calculated results reveal that EEF has definite influence on the trigger bond of SYX-9, especially in positive direction, and the shortening of the trigger bond caused by it can effectively reduce the sensitive of SYX-9. In addition, EEF has an effect on the electron density of SYX-9. The positive EEF can reduce the HOMO-LUMO gap. From the perspective of components of energy variation and the force on atoms, the factors of structural deformation are specifically investigated. The aromaticity of SYX-9 makes its structure stable under the influence of EEF, which is verified by the method of the iso-chemical shielding surface (ICSS).
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Li L, Shi B, Lu LM, Zhao XH, Hu DY, Tang TY, Tang YL. Study on the Structure, UV Spectrum, Dissociation and Active Sites of Trichlorotrifluoroethane (CFC-113A) Molecule under External Electric Field. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2022. [DOI: 10.1134/s0036024422090217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Zhang R, Xia W, Xu X, Ma P, Ma C. Theoretical study on BTF-based cocrystals: effect of external electric field. J Mol Model 2022; 28:185. [PMID: 35687201 DOI: 10.1007/s00894-022-05178-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 05/30/2022] [Indexed: 11/24/2022]
Abstract
The external electric field plays an important role in the sensitivity of cocrystal energetic materials. To reveal the influence of external electric field on benzotrifuroxan/2,4,6-trinitroaniline (BTF/TNA), benzotrifuroxan/trinitroazetidine (BTF/TNAZ), benzotrifuroxan/1,3,5-trinitrobenzene (BTF/TNB), and benzotrifuroxan/trinitrotoluene (BTF/TNT) cocrystals' sensitivity, atoms in molecules (AIM), frontier molecular orbitals, nitro group charges (QNO2), electron density values (ρ), electrostatic surface potentials (ESPs), bond dissociation energy (EBDE), and interaction energy (Eint) of the C-NO2 bond were calculated by density functional theory at M062X-D3/ma-def2 TZVPP and B3LYP-D3/6-311 + G (d, p) levels in this article. The results indicate that both negative and positive electric fields reduce the energy gap of the BTF-based cocrystals, and BTF/TNAZ is the most sensitive cocrystal among the four cocrystals. For BTF/TNA and BTF/TNB, the EBDE and the negative charge of the nitro group decreases with increasing positive electric field strength, the Vs max increases with positive electric field strength, and the sensitivity of cocrystal eventually tends to increase under the positive electric field. For BTF/TNAZ and BTF/TNT, the EBDE and the negative charge of the nitro group decrease with increasing negative electric field strength, the Vs max increases with negative electric field strength, and the sensitivity of cocrystal eventually tends to increase under the negative electric field. Finally, the variation in bond length, nitro charge, and AIM electron density values are well correlated with the strengths of the external electric field.
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Affiliation(s)
- Renfa Zhang
- College of Safety Engineering and Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Wenxin Xia
- College of Safety Engineering and Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Xiaosong Xu
- College of Safety Engineering and Engineering, Nanjing Tech University, Nanjing, 210009, China
| | - Peng Ma
- College of Safety Engineering and Engineering, Nanjing Tech University, Nanjing, 210009, China.
| | - Congming Ma
- College of Safety Engineering and Engineering, Nanjing Tech University, Nanjing, 210009, China. .,Wisdom Pharmaceutical Co., Ltd, Nantong, China.
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Xu X, Zhang R, Xia W, Ma P, Ma C. Study on regulation effect of external electric field on energetic material 1-methyl-2,4,5-Trinitroimidazole. J Mol Graph Model 2022; 116:108237. [DOI: 10.1016/j.jmgm.2022.108237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/25/2022] [Accepted: 05/26/2022] [Indexed: 11/30/2022]
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Xu X, Zhang R, Xia W, Ma P, Ma C, Pan Y, Jiang J. Density Functional Theory Study of CL-20/Nitroimidazoles Energetic Cocrystals in an External Electric Field. COMPUT THEOR CHEM 2022. [DOI: 10.1016/j.comptc.2022.113607] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sun KB, Zhang SH, Ren FD, Hao YP, Ba SH. Theoretical prediction of the trigger linkage, cage strain, and explosive sensitivity of CL-20 in the external electric fields. J Mol Model 2021; 27:85. [PMID: 33598779 DOI: 10.1007/s00894-020-04634-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 12/02/2020] [Indexed: 11/24/2022]
Abstract
In order to add safely external electric fields into the systems of the explosives with strong cage strain, the effects of the external electric fields on the strengths of trigger linkages, cage strain energies (CSEs), surface electrostatic potentials (ESPs), as well as impact and shock initiation sensitivities of CL-20 were investigated using the B3LYP and M06-2X methods with 6-311++G(2d,p) basis set. The results show that the changes of the strengths of the N-NO2 bonds are more notable than those of the bonds forming cage, and the changes involving the N-NO2 bonds attached to the five-membered ring are more significant than those attached to the six-membered ring. In most cases, the CSEs in the electric fields are stronger than those in no field. From the BDEs, the N-NO2 cleavage is the decomposition reaction pathway in detonation initiation. However, from the surface ESPs, the N-NO2 cleavage, C-N and C-C bond breaking may initiate the reactions. The global ESPs are more reasonable and reliable to estimate the impact sensitivities of the cage-shaped explosives. The changes of the bond lengths, Mulliken bond orders, nitro group charges and BDEs correlate well with the external electric field strengths. Interestingly, an abnormal result is found that the h50 values in the electric fields are larger than those in no field.
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Affiliation(s)
- Kang-Bo Sun
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China. .,School of Equipment Engineering, Shenyang Ligong University, Shenyang, 110159, China.
| | - Shu-Hai Zhang
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China.
| | - Fu-de Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China
| | - Yong-Ping Hao
- School of Equipment Engineering, Shenyang Ligong University, Shenyang, 110159, China
| | - Shu-Hong Ba
- School of Equipment Engineering, Shenyang Ligong University, Shenyang, 110159, China
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Molecular polarizabilities of some energetic compounds. J Mol Model 2021; 27:51. [PMID: 33502608 DOI: 10.1007/s00894-020-04540-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/13/2020] [Indexed: 10/22/2022]
Abstract
The dependence of sensitivity of an explosive on its molecular structure may be mainly attributed to the molecular deformability, which can be expressed by some characteristic parameters, resonance energy for aromatic an explosive, strain energy for a strained-ring or strained-cage explosive, large π-π separation energy for a large π-π linked-explosive, bond rotational energy barriers of C-NO2, N-NO2, O-NO2 for C-NO2, N-NO2, O-NO2 bond-based explosives, and so on. Molecular polarizability of an explosive is also an important molecular deformability index, which can be effectively used to compare impact sensitivities of explosive's isomers, isoelectronic species, and similar structures. Interestingly, comparing the molecular polarizabilities under external electric fields with different energy levels of isomeric N20(Ih) and N20(D3d) clusters and the Mo2N20 and Re2N20 complex compounds, it is found that there are different energy thresholds of significant molecular expansion.
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Ren FD, Shi WJ, Cao DL, Li YX, Zhang DH, Wang XF, Shi ZY. External electric field reduces the explosive sensitivity: a theoretical investigation into the hydrogen transference kinetics of the NH 2NO 2∙∙∙H 2O complex. J Mol Model 2020; 26:351. [PMID: 33241433 DOI: 10.1007/s00894-020-04607-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 11/08/2020] [Indexed: 11/25/2022]
Abstract
Controlling the selectivity of detonation initiation reaction to reduce the explosive sensitivity has been a Holy Grail in the field of energetic materials. The effects of the external electric fields on the homolysis of the N-NO2 bond and initiation reaction dynamics of NH2NO2∙∙∙H2O (i.e., intermolecular and 1,3-intramolecular hydrogen transfers) were investigated at the MP2/6-311++G(2d,p) and CCSD/6-311++G(2d,p)//MP2/6-311++G(2d,p) levels. The results show that the N-NO2 bond is not the "trigger linkage." The notable transiliences of the activation energy of the intermolecular hydrogen transfer are found with the field strength of - 0.012 a.u. along the -x-direction, leading to the conversion of the main reaction between the intermolecular and 1,3-intramolecular hydrogen transference. The activation energies of two kinds of the hydrogen transferences are increased under the external electric fields along the -y-direction. In particular, due to the conversion of the main reaction, the activation energies of the overall reaction are increased significantly along the -x-direction, leading to the significant reduced explosive sensitivities. Therefore, by controlling the field strengths and orientations between the "reaction axis" and external electric field along the y- and x-directions, the selectivity of the initiation reaction could be controlled and the explosive sensitivity could be reduced. Employing AIM (atoms in molecules) and surface electrostatic potentials, the origin of the control of reaction selectivity and the reduction of sensitivity is revealed. This work is of great significance to the improvement of the technology that the external electric fields are added safely into the energetic material system to enhance the explosive performance. Graphical abstract.
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Affiliation(s)
- Fu-de Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China.
| | - Wen-Jing Shi
- Second Hospital of Shanxi Medical University, Taiyuan, 030053, China
| | - Duan-Lin Cao
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China
| | - Yong-Xiang Li
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China
| | - De-Hua Zhang
- Shanxi North Jindong Chemical Industries Co., Ltd, Yangquan, 045000, China
| | - Xian-Feng Wang
- Shanxi North Jindong Chemical Industries Co., Ltd, Yangquan, 045000, China
| | - Zhao-Yang Shi
- Shanxi North Jindong Chemical Industries Co., Ltd, Yangquan, 045000, China
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Bai ZX, Zeng W, Tang B, Fan DH, Liu QJ, Jiang CL, Chang XH. Effects of molecular vacancy and ethylenediamine on structural and electronic properties of CH 3NO 2 surfaces. J Mol Model 2020; 26:209. [PMID: 32681287 DOI: 10.1007/s00894-020-04476-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Accepted: 07/14/2020] [Indexed: 11/30/2022]
Abstract
The structural and electronic properties of (100) surface for nitromethane (NM) are studied using density functional theory (DFT) with the generalized gradient approximation and Perdew-Burke-Ernzerhof functional (GGA-PBE). Molecular vacancy and ethylenediamine (C2H8N2) substitution are considered in this work. We find that ethylenediamine substitution significantly decreases the band gap, while molecular vacancy increases the band gap slightly. It indicates that ethylenediamine substitution has a positive effect on the impact sensitivity of NM. Also, the formation energies are calculated and the reasons for the decrease of band gap for ethylenediamine substitution and the increase of band gap for CH3NO2 vacancy are explained.
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Affiliation(s)
- Zhi-Xin Bai
- School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031, Sichuan, People's Republic of China
| | - Wei Zeng
- Teaching and Research Group of Chemistry, College of Medical Technology, Chengdu University of Traditional Chinese Medicine, Chengdu, 610075, People's Republic of China
| | - Bin Tang
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Dai-He Fan
- School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031, Sichuan, People's Republic of China
| | - Qi-Jun Liu
- School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031, Sichuan, People's Republic of China
| | - Cheng-Lu Jiang
- School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031, Sichuan, People's Republic of China.
| | - Xiang-Hui Chang
- School of Physical Science and Technology, Key Laboratory of Advanced Technologies of Materials, Ministry of Education of China, Southwest Jiaotong University, Chengdu, 610031, Sichuan, People's Republic of China.
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Hao L, Wang J, Zhai D, Ma P, Ma C, Pan Y, Jiang J. Theoretical Study on CL-20-Based Cocrystal Energetic Compounds in an External Electric Field. ACS OMEGA 2020; 5:14767-14775. [PMID: 32596614 PMCID: PMC7315606 DOI: 10.1021/acsomega.0c01643] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 05/29/2020] [Indexed: 05/26/2023]
Abstract
An external electric field has great effects on the sensitivity of cocrystal energetic materials. In order to find out the relationship between the external electric field and sensitivity of cocrystals 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/benzotrifuroxan (CL-20/BTF), 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/3,4-dinitropyrazole (CL-20/DNP), and 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane/1-methyl-3,5-dinitro-1,2,4-triazole (CL-20/MDNT), density functional theory at B3LYP-D3/6-311+G(d,p) and M062X-D3/ma-def2 TZVPP levels was employed to calculate frontier molecular orbitals, atoms in molecules (AIM) electron density values, bond dissociation energies (BDEs) of the N-NO2 bond, impact sensitivity (H 50), electrostatic potentials (ESPs), and nitro group charges (Q NO2 ) in this work. The results show that a smaller highest occupied molecular orbital-lowest unoccupied molecular orbital gap and the BDEs, as well as H 50, tend to have a larger sensitivity along with the positive directions in the external electric field. Moreover, a smaller local positive ESP (V s max) leads to better stability in the negative electric field. The sensitivity of cocrystal molecules decreases gradually in the negative external electric field with the increase of negative nitro group charges. Finally, the change in the bond lengths, AIM electron density values, and nitro group charges correlate well with the external electric field strengths.
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Affiliation(s)
- Lina Hao
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Jinpeng Wang
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Diandian Zhai
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Peng Ma
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Congming Ma
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Yong Pan
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Juncheng Jiang
- College of Safety Science and Engineering, Nanjing Tech University, Nanjing 211816, China
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Wang BG, Ren FD, Wang Y. Theoretical prediction of the trigger linkages, surface electrostatic potentials, and explosive sensitivities of 1,4-dinitroimidazole-N-oxide in the external electric fields. J Mol Model 2019; 25:368. [PMID: 31776690 DOI: 10.1007/s00894-019-4258-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 11/12/2019] [Indexed: 10/25/2022]
Abstract
In order to introduce effectively the external electric fields into the explosive systems, the change trends of the strengths of trigger linkages, nitro group charges, and explosive sensitivities of 1,4-dinitroimidazole-N-oxide (1,4-DNIO) were investigated in the external electric fields at the B3LYP/6-311++G(2d,p) and M06-2X/aug-cc-pVTZ levels. The formulas for calculating the impact sensitivity by the surface electrostatic potentials were discussed. The results show that the N-NO2 bond is always the most likely trigger linkage, followed by N → O. This is the very valuable information for the researchers engaged in the molecular design or synthesis of the energetic explosives: The influences of the weak N → O coordination bond attached to the aromatic ring on the explosive sensitivity can be ignored when the N-NO2 bond exists. In the external electric fields along the positive directions of the N → O and C-NO2 bond axes as well as the negative direction of the N-NO2 bond axis, the dissociation energies (BDEs) of the N-NO2 bond and h50 values are increased, leading to the decreased impact sensitivities. The changes of the bond lengths, AIM electron density values, nitro group charges, BDEs of the trigger linkages, and impact sensitivities correlate well with the external electric field strengths, respectively. The effects of the fields on the electric spark sensitivities and shock initiation pressures are not obvious. The essence of the low BDEs of the N-NO2 bond was revealed by the resonance theory of the aromatic ring. Graphical abstract Changes of the impact sensitivities versus field strengths.
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Affiliation(s)
- Bao-Guo Wang
- School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China
| | - Fu-de Ren
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China.
| | - Yong Wang
- School of Chemical Engineering and Technology, North University of China, Taiyuan, 030051, China
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Wang Y, Ren FD, Cao DL. A dynamic and electrostatic potential prediction of the prototropic tautomerism between imidazole 3-oxide and 1-hydroxyimidazole in external electric field. J Mol Model 2019; 25:330. [PMID: 31659461 DOI: 10.1007/s00894-019-4216-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/24/2019] [Indexed: 10/25/2022]
Abstract
In order to obtain an optimum scheme for separating the proton-transfer tautomer, a dynamic investigation into the effect of the external electric field on the proton-transfer tautomeric conversion in imidazole 3-oxide and 1-hydroxyimidazole was carried out at the M06-2X/6-311++G** and CCSD(T)/6-311++G(2d,p) level, accompanied by the analysis of the surface electrostatic potentials. The results show that, for both the forward reaction "imidazole 3-oxide → N-hydroxyimidazole free radical → 1-hydroxyimidazole" and its reverse reaction processes, the fields parallel to the N→O or N-OH bond axis affect the barrier heights and rate constants considerably more than those parallel to the other orientations. As the field strength is increased along the orientation from the O to N atom, the chemical equilibrium moves toward the direction for the formation of 1-hydroxyimidazole, while the amount of imidazole 3-oxide is increased with the increased field strength along the opposite orientation. In the fields along the orientation consistent with the dipole moment, the electrostatic potentials and their variances "abnormally" increase for the transition states with the N→O bond in comparison with those in no field (they decrease generally), which enhances the nucleophilicity of the coordination O atom and the electrophilicity of the activated H atom. The analyses of the AIM (atoms in molecules) and NICS (nucleus-independent chemical shift) were used to explain the above anomaly. Graphical Abstract Electrostatic potentials and their variances "abnormally" increase in the external electric field, which greatly affects tautomeric conversion.
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Affiliation(s)
- Yong Wang
- School of Chemical Engineering and Technology, North University of China, Shanxi Taiyuan, 030051, China
| | - Fu-de Ren
- School of Chemical Engineering and Technology, North University of China, Shanxi Taiyuan, 030051, China.
| | - Duan-Lin Cao
- School of Chemical Engineering and Technology, North University of China, Shanxi Taiyuan, 030051, China
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Liu Y, Ma Y, Yu T, Lai W, Guo W, Ge Z, Ma Z. Structural Rearrangement of Energetic Materials under an External Electric Field: A Case Study of Nitromethane. J Phys Chem A 2018; 122:2129-2134. [PMID: 29437398 DOI: 10.1021/acs.jpca.7b11097] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
As a significant stimulus, the external electric field (EEF) can change the decomposition mechanism and energy release of energetic materials (EMs). Hence, understanding the response of EMs to an EEF is greatly meaningful for their safe usage. Herein, the structural arrangement, a crucial factor in the impact sensitivity and detonation performance of EMs, under the EEF ranging from 0.0 to 0.5 V/Å was investigated via molecular dynamics simulation. Nitromethane (NM) was taken as a case study due to the simple structure. The simulation results show that there exists a critical EEF strength between 0.2 and 0.3 V/Å, which can induce the transition of NM molecules from relatively disordered distribution to solidlike ordered and compacted arrangement with a large density. In this ordered structure, NM dipoles are aligned in a head-to-tail pattern parallel to the EEF direction because of the favored dipole-dipole interactions and weak C-H···O hydrogen bonds. As the EEF strength is enhanced, the potential energy and cohesive energy density of the NM system gradually decrease and increase, respectively, indicative of high thermodynamics stability of ordered arrangement. The results reported here also shed light on the potential of the EEF to induce the nucleation and crystallization to explore new polymorphs of EMs.
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Affiliation(s)
- Yingzhe Liu
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Yiding Ma
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Tao Yu
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Weipeng Lai
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Wangjun Guo
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Zhongxue Ge
- State Key Laboratory of Fluorine & Nitrogen Chemicals, Xi'an Modern Chemistry Research Institute , Xi'an 710065, P. R. China
| | - Zhinan Ma
- School of Science, North University of China , Taiyuan 030051, P. R. China.,Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Nankai University , Tianjin 300071, P. R. China
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