1,2-Bis(nitroazol-1-yl)diazenes: improved methods of synthesis, determination of the enthalpies of formation, and calculations of main energy characteristics of solid composite propellants based on these compounds

Thermal stability of emerging N6-type energetic materials: kinetic modeling of simultaneous thermal analysis data to explain sensitivity trends

“…1,2-Bis(3-nitro-1 H -1,2,4-triazol-1-yl)diazene ( 3 ) was synthesized from 3-nitro-1 H -1,2,4-triazole in two steps (43% overall yield) in accordance with the reported procedure. 30,31 1 H NMR (300.1 MHz, DMSO-d 6 ): δ = 10.03 ppm; 13 C NMR (75.47 MHz, acetonitrile-d 3 ): δ = 148.5, 162.7 ppm. Elemental analysis calcd for C 4 H 2 N 10 O 4 : C, 18.91; H, 0.79; N, 55.12; found: C, 19.01; H, 0.80; N, 54.79.…”

“…The value of E a1 (138 AE 6 kJ mol À1 ), if the process is dominated by vaporization, should be equal to the sublimation enthalpy at average measurement temperature. We tried to obtain the target value from the reported experimental enthalpy of formation of solid 3 (725 AE 3 kJ mol À1 ) 31 and calculated enthalpy of formation in gas phase (566 kJ mol À1 ). 30 But the latter value seems to be incorrectly reported as it should be larger than the former.…”

“…As a result, these compounds perform slightly better (1) than or similar (2) to the benchmark nitramine high explosive HMX. In addition, we consider another molecule with the N-N-N = N-N-N fragment, 1,2-bis(3-nitro-1H-1,2,4-triazol-1-yl)diazene (3), 30,31 as well as two structurally relevant compounds without the N6 bridge, 4,4 0 ,5,5 0 -tetranitro-2H,2 0 H-3,3 0 -bipyrazole (4) 32,33 and 5,5 0 -dinitro-2H,2 0 H-3,3 0 -bi-1,2,4-triazole (5). 34 A comparative analysis of the thermal behavior and decomposition kinetics of 1-5 should benefit the understanding of how the N6-fragment contributes to the thermal stability of the materials (Fig.…”