“…Note that our calculations do not support the mechanistic assumptions made before on the primary decomposition channel of 5-ADP and polynitro pyrazole congeners (Schemes 1, 2 and 4). 37,39,40,[42][43][44][45] On the contrary, the present results agree with the mechanism proposed earlier for 3,5-dinitropyrazole (Scheme 3). 41 Furthermore, the radical R7 turned out to be very stable kinetically with respect to monomolecular decomposition (Fig.…”
Section: Discussion On the Experimental And Computational Data And Th...supporting
confidence: 93%
“…In contrast to above discussed results, on the basis of isothermal manometry studies, Prokudin et al 42,43 hypothesized a primary decomposition reaction of a series of di-and trinitropyrazole derivatives to be analogous to that of nitroalkenes, viz., an intramolecular oxidation (Scheme 4). In the latter case, the authors also noted a strong self-acceleration attributed to the catalytic action of the condensed products.…”
Section: Introductionmentioning
confidence: 92%
“…41 Scheme 4 The hypothetical intramolecular oxidation mechanism of polynitro pyrazole derivatives proposed in the literature. 42,43 approximation 62 was used to accelerate convergence of the SCF components of DLPNO-CCSD(T) energy. The corresponding auxiliary basis sets (aug-cc-pVQZ/JK and aug-cc-pVQZ/C in the ORCA nomenclature) 63 were used in the DF calculations of the SCF and correlation energies.…”
A reliable kinetic description of the thermal stability of energetic materials (EM) is very important for safety and storage-related problems. Among other related issues, autocatalysis very often complicates the decomposition...
“…Note that our calculations do not support the mechanistic assumptions made before on the primary decomposition channel of 5-ADP and polynitro pyrazole congeners (Schemes 1, 2 and 4). 37,39,40,[42][43][44][45] On the contrary, the present results agree with the mechanism proposed earlier for 3,5-dinitropyrazole (Scheme 3). 41 Furthermore, the radical R7 turned out to be very stable kinetically with respect to monomolecular decomposition (Fig.…”
Section: Discussion On the Experimental And Computational Data And Th...supporting
confidence: 93%
“…In contrast to above discussed results, on the basis of isothermal manometry studies, Prokudin et al 42,43 hypothesized a primary decomposition reaction of a series of di-and trinitropyrazole derivatives to be analogous to that of nitroalkenes, viz., an intramolecular oxidation (Scheme 4). In the latter case, the authors also noted a strong self-acceleration attributed to the catalytic action of the condensed products.…”
Section: Introductionmentioning
confidence: 92%
“…41 Scheme 4 The hypothetical intramolecular oxidation mechanism of polynitro pyrazole derivatives proposed in the literature. 42,43 approximation 62 was used to accelerate convergence of the SCF components of DLPNO-CCSD(T) energy. The corresponding auxiliary basis sets (aug-cc-pVQZ/JK and aug-cc-pVQZ/C in the ORCA nomenclature) 63 were used in the DF calculations of the SCF and correlation energies.…”
A reliable kinetic description of the thermal stability of energetic materials (EM) is very important for safety and storage-related problems. Among other related issues, autocatalysis very often complicates the decomposition...
“…The Prokudin group's study showed that the thermal decomposition of the nitropyrazole derivatives may start from the intramolecular oxidation of the adjacent carbon atom by the nitro group, which proceeds via a strongly polarized cyclic four-membered transition state. [32] These reported mechanisms from the literature indicate that the pyrolysis of the nitropyrazole derivatives may include different kinds of pathways, such as hydrogen shift, the elimination of N 2, as well as internal redox reactions. To further prove the results obtained from the in situ FTIR spectroscopy experiments and calculations based on the ReaxFF force field, the DSC-TG-FTIR-MS quadruple technology [33] was then applied to perform the real-time and continuous analysis of the gaseous products during the pyrolysis of LLM-116 and LLM-226.…”
Dinitropyrazole is an important structure for the design and synthesis of energetic materials. In this work, we reported the first comparative thermal studies of two representative dinitropyrazole-based energetic materials, 4-amino-3,5-dinitropyrazole (LLM-116) and its novel trimer derivative (LLM-226). Both the experimental and theoretical results proved the active aromatic N-H moiety would cause incredible variations in the physicochemical characteristics of the obtained energetic materials. Thermal behaviors and kinetic studies of the two related dinitropyrazole-based energetic structures showed that impressive thermal stabilization could be achieved after the trimerization, but also would result in a less concentrated heat-release process. Detailed analysis of condensed-phase systems and the gaseous products during the thermal decomposition processes, and simulation studies based on ReaxFF force field, indicated that the ring opening of LLM-116 was triggered by hydrogen transfer of the active aromatic N-H moiety. In contrast, the initial decomposition of LLM-226 was caused by the rupture of carbon-nitrogen bonds at the diazo moiety.
“…Pyrazoles are one of the important classes of compounds [4][5][6][7]. These compounds can be widely used in medicine, pesticides, photosensitive materials, fine chemicals [8][9][10].…”
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