Thermal stability of 3,4,5-trinitropyrazole and its ammonium salt

Autocatalytic decomposition of energetic materials: interplay of theory and thermal analysis in the study of 5-amino-3,4-dinitropyrazole thermolysis

“…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.…”

“…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.…”

“…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.…”

Delving into Autocatalytic Liquid-State Thermal Decomposition of Novel Energetic 1,3,5-Triazines with Azido, Trinitroethyl, and Nitramino Groups

“…The fact that the decomposition reaction of the compounds proceeds in melt was included in the formal reaction model. The typical ratio between the rate constants in liquid and solid states, also called the retardation coefficient K T , is nearly constant for common energetic materials: , K T = k liq / k sol ≈ 100 ± 50. Thus, we introduce the triggering temperature T * equal to the melting peak temperature; below T * the preexponential factor is reduced by 100 times imitating the retardation by crystal lattice.…”

5‐Amino‐3,4‐dinitropyrazole as a Promising Energetic Material

“…Since high activatione nergy is obtained along with high pre-exponential factor,i ti sn ot straightforward to estimate the thermal stability of the compound studied.T his could be done by comparisono ft he calculated rate constant with the ones reported in literature. Thus, the rate constant at 80 8Ci se qual to 2 10 À11 s À1 ,e xceedingt he reported for RDX valueo f1 0 À12 s À1 [36].M ore precise determinationo f the 5-amino-3,4-dinitropyrazole thermal stability was performed using accelerating rate calorimetry (ARC), knownt o be more sensitive than DSC due to increased sample mass [37].T he detected onset is 173 8C ( Figure 5), which is lower than the values measured for RDX (197 8C) and hexanitrohexaazaisowurtzitane CL-20( 181 8C) undert he same conditions. Thus, the 5-ADPt hermal stability is slightly lower than RDX or CL-20, but is well above the critical level of 150 8C [38].…”