98%
921
2 minutes
20
As a follow-up to our investigation into the effect of external electric field on the chemical bond strength, the effects of external electric field on the CH3NO2 → CH3ONO isomerization dynamics were investigated using the MP2/6-311++G(2d,p) and CCSD/6-311++G(2d,p) methods. The rate constants in the absence and presence of various field strengths were calculated. The results show that, when the field strength is larger than +0.0060 a.u. along the C-NO2 bond axis, the barriers of the isomerization are lower than the C-NO2 bond dissociation energies, leading to the preferences of the isomerization over the C-NO2 bond dissociation. In this case, the sensitivities are higher than that in no field. However, in the other fields, the C-NO2 bond scission is favored and the sensitivities are almost equal to that in no field. Several good linear correlations are found between the field strengths and the changes of the bond lengths or corresponding electron densities.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s00894-016-2966-4 | DOI Listing |
J Chem Phys
March 2025
Research Center of Advanced Biological Manufacture, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
Condensed phase explosives typically contain defects such as voids, bubbles, and pores; this heterogeneity facilitates the formation of hot spots and triggers decomposition reaction at low densities. The study of the thermal decomposition mechanisms of explosives at different densities has thus attracted considerable research interest. Gaining a deeper insight into these mechanisms would be helpful for elucidating the detonation processes of explosives.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2021
School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, P. R. China.
The potential energy surfaces (PESs) of three nitrotoluene isomers, such as p-nitrotoluene, m-nitrotoluene, and o-nitrotoluene, have been theoretically built at the CCSD(T)/CBS level. The geometries of reactants, transition states (TSs) and products are optimized at the B3LYP/6-311++G(d,p) level. Results show that reactions of -NO2 isomerizing to ONO, and C-NO2 bond dissociation play important roles among all of the initial channels for p-nitrotoluene and m-nitrotoluene, and that the H atom migration and C-NO2 bond dissociation are dominant reactions for o-nitrotoluene.
View Article and Find Full Text PDFMolecules
December 2018
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
The initial channels of thermal decomposition mechanism of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) molecule were investigated. The results of quantum chemical calculations revealed four candidates involved in the reaction pathway, including the C⁻NO₂ bond homolysis, nitro⁻nitrite rearrangement followed by NO elimination, and H transfer from amino to acyl O and to nitro O with the subsequent OH or HONO elimination, respectively. In view of the further kinetic analysis and ab initio molecular dynamics simulations, the C⁻NO₂ bond homolysis was suggested to be the dominant step that triggered the decomposition of LLM-105 at temperatures above 580 K.
View Article and Find Full Text PDFMolecules
June 2018
Department of Physical Sciences, Nicholls State University, P.O. Box 2022, Thibodaux 70310, LA, USA.
A deactivation channel for laser-excited 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) was studied by semiclassical dynamics. Results indicate that the excited state resulting from an electronic transition from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular mrbital (LUMO) is deactivated via pyramidalization of the activated N atom in a nitro group, with a lifetime of 2.4 ps.
View Article and Find Full Text PDFJ Mol Model
May 2016
Department of Chemistry, University of Science and Technology - The University of Danang, 54 Nguyen Luong Bang, Lien Chieu, Da Nang, Vietnam.
Two-layer ONIOM method at the ONIOM(B3LYP/6-31G(d):PM6) level of theory was applied to study the cycloaddition reaction of α-chlorocarbanions (CR2Cl(─), where R is H, Cl, CH3 CN, and NO2) and fullerene. The results show that the reaction pathways depend on the electron withdrawing functional groups or the electron donating functional groups contained in the α-chlorocarbanions. The energy profile analysis reveals that functionalization of fullerene by CCl3 (─), C(CH3)2Cl(─), and CH2Cl(─) is more favorable than by C(CN)2Cl(─) and C(NO2)2Cl(─) in terms of the thermodynamic point of view.
View Article and Find Full Text PDF