Synthesis, Crystal Structure And Thermal Behavior Of Unsymmetrical 1,2,4,5-tetrazine

Five unsymmetrical substituted s-tetrazine compounds were synthesized in this thesis. These compouds are 3-nitroguanyl-6-?3,5-dimethylpyrazol-lyl?-1,2,4,5-tetrazine ?NDT?, 3-hydrazine-6-?3,5-dimethylpyrazol-lyl?-1,2,4,5-tetrazine ?DPHT?,3-[?3-methoxy-4-hydroxyphenyl?methylenehydrazone]-6-?3,5-dimethylpyrazol-lyl?-1,2,4,5-tetrazine ?DMPT?, 3-[?pmethoxyphenyl?methylene hydrazone]-6-?3,5-dimethylpyrazol-l yl?-1,2,4,5-tetrazine ?DPMHT? and 3-amino-6-?3,5-dimethylpyrazol-1-yl?-[1,2,4]triazolo[4,3-b]-[1,2,4,5] tetrazine ?ADTTz?. All the prepared compounds were characterized by elemental analysis, NMR and IR. The single crystals of NDT, DPHT, DMPT and ADTTz were obtained and determined which lists as below:NDT-DMF:C₁₁H₁₇N₁₁O₃, Triclinic, P-1;DPHT·H₂O:C₇H₁₂N₈O, Monoclinic, P2₁/c;DMPT:C₁₅H₁₆N₈O₂, Monoclinic, P2₁/n;2ADTTZ·H₂O:C₁₆H₂₀N₁₈₀, Monoclinic, P2₁/n.In order to study the thermal behavior of unsymmetrical substituted s-tetrazine compounds, the differential scanning calorimetry ?DSC? and thermogravimetry ?TG? techniques were used to measure the thermal decomposition process of NDT, DMPT, DPMHT and ADTTz under a non-isothermal condition. The thermal decomposition kinetic parameters and thermal decomposition kinetics equations were obtained by the Kissinger, Ozawa and integral method. The entropy of activation, enthalpy of activation and Gibbs free energy of activation of compounds were obtained.To evaluate the thermal safety of the as-prepared compounds, the self-accelerating decomposition temperature, the critical temperatures of thermal explosion and the thermal ignition temperature were calculated. The specific heat capacity of NDT, DMPT, DPMHT and ADTTz were determined with continuous Cp mode of Micro-DSC III. The thermodynamic functions of compounds were obtained, relative to the standard temperature 298.15 K. The adiabatic time-to-explosion of compounds were calculated by the relationship between Cp and T and the thermal decomposition parameters. In order to evaluate the detonation properties of the compounds, the detonation velocity and detonation pressure of NDT, DPHT, DMPT and ADTTz were predicted from the nitrogen equivalent equations.