From N-amino to N-azo derivatives: Influence of the structure of isomeric azo derivatives of dinitropyrazoles on their decomposition and combustion mechanism

From N-amino to N-azo derivatives: Influence of the structure of isomeric azo derivatives of dinitropyrazoles on their decomposition and combustion mechanism Научная публикация

Журнал

FirePhysChem
ISSN: 2667-1344

Вых. Данные

Год: 2026, DOI: 10.1016/j.fpc.2026.06.004

Ключевые слова

Combustion, 1,2-bis(3,4-dinitro-1H-pyrazol-1-yl)diazen, 1,2-bis(3,5-dinitro-1H-pyrazol-1-yl)diazen pyrazole, thermal decomposition kinetics, combustion mechanism, safety predictions

Авторы

Sinditskii Valery P. ¹ , Melnikova Ludmila Ya. ¹ , Smirnova Anastasia D. ¹ , Manakhova Ekaterina S. ¹ , Yudin Nikolay V. ¹ , Dalinger Igor L. ² , Konnov Alexei A. ² , Klenov Michail S. ²

Организации

1	Mendeleev University of Chemical Technology, Moscow, Miusskaya Sq. 9, Russia
2	Zelinsky Institute of Organic Chemistry, Russian Academy of Science, Moscow, Leninsky Pros., 47, Russia

The study investigates the thermal stability and combustion characteristics of isomeric 1,2-bis(dinitro-1H-pyrazol-1-yl)diazenes. The investigation of thermal decomposition revealed that over a wide temperature range, the activation energies for the decomposition of two isomeric molecules, 1,2-bis(3,4-dinitro-1H-pyrazol-1-yl)diazen (3,4-DNPAz) and 1,2-bis(3,5-dinitro-1H-pyrazol-1-yl)diazen (3,5-DNPAz), are relatively low: 145.2 and 134.6 kJ·mol-1, respectively. It is suggested that the rate-limiting step is the isomerization of azo groups from the more stable trans form to the less stable cis form, rather than monomolecular N-N bond breaking. In the case of the 3,5-DNPAz isomer, the proximity of the nitro group to the azo linkage significantly facilitates the trans-cis isomerization reaction. The study of the combustion behavior of two isomeric azo compounds revealed an unusually large difference in their burning rates. Thermocouple studies indicated that the surface temperatures of 3,5-DNPAz are close to the surface temperatures of RDX, while the surface temperatures of 3,4-DNPAz are significantly higher. The combustion of isomeric azo compounds was found to follow different mechanisms, which are associated with the different thermal stabilities and volatilities of their parent dinitropyrazole isomers. Thermal safety predictions were made, and thermodynamic studies were conducted for azonitropyrazoles.

Sinditskii V.P. , Melnikova L.Y. , Smirnova A.D. , Manakhova E.S. , Yudin N.V. , Dalinger I.L. , Konnov A.A. , Klenov M.S.
From N-amino to N-azo derivatives: Influence of the structure of isomeric azo derivatives of dinitropyrazoles on their decomposition and combustion mechanism
FirePhysChem. 2026. DOI: 10.1016/j.fpc.2026.06.004 OpenAlex

Поступила в редакцию:	24 февр. 2026 г.
Принята к публикации:	13 июн. 2026 г.
Опубликована online:	14 июн. 2026 г.

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