Synthesis,Structures And Properties Of 1,2,4,5-teazinone Derivatives

As high nitrogen content heterocycles,1,2,4,5-tetrazine derivatives have been widely studied due to their excellent detonation properties,good thermal stability and low sensitivity.However,the derivatives of unsymmetrical 1,2,4,5-tetrazine are seldom studied.In this paper,five 1,2,4,5-teazinone derivatives were synthesized and characterized by ¹HNMR,¹³CNMR,EA and IR.They are as follows:6-（3,5-dimethyl-1H-pyrazol-1-yl）-1,2,4,5-tetrazin-3（2H）-one（DPTzO）,potassium salt （K·DPTzO）,Guanidinium salt （G·DPTzO）6-（1H-tetrazol-5-yl）amion-1,2,4,5-tetrazin-3（2H）-one（TATzO）,potassium salt of TATzO（K₂·TATzO）.Meantime,the single crystal of them were obtained by suitable method.The crystal structures were determined by X-ray single crystal diffractometer and can be seen as follow:DPTzO:C₇H₈N₆O,Orthorhombic,Pna2₁;[2K·DPTzO（2H₂O）]·H₂O:C₁₄H₂₀K₂N₁₂O₅,Monoclinic,C2/c;G·DPTzO:C₈H₁₃N₉O,Monoclinic,P2₁/c;TATzO·H₂O:C₃H₅N₉O₂,Orthorhombic,Pnma;[K₂·TATzO（H₂O）]:C₃H₃K₂N₉O₂,Triclinic,P-1.Furthermore,the thermal behavior of the tetrazinone derivatives were investigated by thermogravimetry-derivative thermogravimetry（TG-DTG）and differential scanning calorimetry （DSC） under non-isothermal conditions.And the thermal decomposition kinetics parameters and thermal decomposition kinetics functions of them were calculated by differential and integral method.Besides,T_SADT,T_be,T_bp,ΔS^≠,ΔH^≠andΔG^≠were calculated to evaluate the thermal safety of them.The detonation performance of DPTzO and TATzO were evaluated by the K-J equation and the nitrogen equivalent formula.Finally,the orbital distribution,Mulliken charge distribution,Mayer bond order,and electrostatic potentia of DPTzO,K·DPTzO,TATzO and K₂·TATzO were analyzed through Gaussian03 software package by B3LYP/6-311+G**level.