Synthesis,Characterization,Quantum Chemical Calculations And Thermal Behavior Of S-tetrazine Derivatives

Six s-tetrazine derivatives have been synthesized in this paper and they are as follows:3-(p-nitrobenzyl methylene)-6-(3,5-dimethylpyrazol-1-yl)hydrazone-s-tetrazine(DPHX),3-(p-hydroxybenzyl methylene)-6-(3,5-dimethylpyrazol-1-yl)hydrazone-s-tetrazine(DPHM),3-(m-dintrobenzyl methylene)-6-(3,5-dimethylpyrazol-1-yl)hydrazone-s-tetrazine(DMHT),3-methylamino-6-(3,5-dimethylpyrazol-1-yl)-s-tetrazine(MDT)3,6-di-(2-butyl-5-chloro-1 H-imidazole-4-methylene)hydrazone-s-tetrazine(BBHT)and 3-(2-butyl-5-chloro-1 H-imidazole-4-methylene)-6-(3,5-dimethy lpyrazol-1-yl)-hydrazone-s-tet razine(BHT).All the synthesized s-tetrazine derivatives were characterized by EA and IR.Meanwhile,the crystals of DPHX,DPHM,DMHT,BBHT and BHT were obtained by slow vaporation and their molecular structures were determined by X-ray single crystal diffractometer.The thermal behavior of DPHX,DPHM,DMHT and MDT was studied by differential scanning calorimetry(DSC)and thermogravimetry(TG)under non-isothermal conditions.And the thermal decomposition kinetics parameters and thermal decomposition kinetics equations of the compounds were calculated by Ozawa method,Kissinger method and integral method.The calculated self-accelerating decomposition temperature,the thermal ignition temperature and the critical temperatures of thermal explosion were used to evaluate the thermal safety of s-tetrazine derivatives.Furthermore,the specific heat capacity of s-tetrazine derivatives was determined by Micro-DSC? microcalorimeter.The thermodynamic functions of the compounds were calculated,meanwhile,the thermodynamic function of the compound was calculated by using Dmol3,and the experimental value was compared with the theoretical value.The detonation performance of the s-tetrazine derivative was evaluated by the detonation velocity and detonation of the compound calculated by the nitrogen equivalent formula.Finally,the molecular structure of the s-tetrazine derivative was analyzed by using Dmol3 of MS to obtain the HOMO-LUMO orbital distribution,charge distribution,bond and thermodynamic functions of the compound with temperature.