Differentiation of the molecular structure of nitro compounds as the basis for simulation of their thermal destruction processes

The effect of isomerization of reactant molecules on the early stage of chemical reaction kinetics

“…The mechanism of decomposition was found to depend on the isomer structure. One more example of model 1 is nitroguanidine, which can exist as ten tautomers and rotational conformers, dif fering in the kinetics and mechanism of thermal decomposition [2]. It was shown that, in some cases, the enthalpy change ΔH upon isomerization is com mensurable with the E a values for the reactions that occur at early stages of decomposition.…”

“…Model 2 considers the first order reaction kinetics, taking into account the presence of two steps in the transformation of compound А 1 into isomer А 2 to give stable intermediate B. This reaction mechanism is suggested for the nitro-nitrate rearrangement of nitroalkanes and for isomerization of nitroalkanes having two H atoms in the α position to the nitro group [1,2]. In this case, the following equations hold for the early stage of the process:…”

“…Nevertheless, in [1,2], the acti vation energy for the elementary step of decomposi tion calculated theoretically for one isomer of an explosive is correlated with the activation energy for decomposition of the explosive determined by formal kinetics methods. Decomposition of explosives is a complex process comprising hundreds of elementary steps [9,10].…”

“…In recent years, the structure and properties of iso mers of some explosives have been studied by mathe matical modeling [1][2][3][4][5]. The dependences of the acti vation energy of thermal decomposition of explosives on the isomer structures have been elucidated, the pos sibility of isomer interconversion has been demon strated, and the energy barriers to isomerization have been determined for different isomerization mecha nisms.…”

“…In this study, mathematical modeling is performed to study the relationship between the experimental kinetic features, in particular, the effective rate con stant (k ef ) for the reaction and the rate constants for the elementary steps (k i ) and the equilibrium con stants (K i ) of isomers for three kinetic models of isomerization proposed previously [2].…”