Researches Of Energetic Pyazole-tetrazine Compounds

Laser initiation technology is a new kind of initiation method that developed fast in recent years.Compared with the conventional technique,it can avoid electrostatic discharge and electromagnetic interference,which enhances its reliability and safety.Searching for photosensitive primary explosives which are sensitive towards input laser stimulation but insensitive towards environmental stimuli（include mechanical,thermal,electromagnetic,radiation,etc.）is important for both the safety in production and the useage in laser initiation technology.In this paper,four series of complexes were synthesized by using tetrazine compounds as ligands,and Co,Ni,Cu and Fe as center metal.In order to find insensitive laser initiation explosives with comprehensive properties,the complexes were characterized,the laser sensitivity and other properties were also tested.The main research contents and achievements are listed as follows:（1）3,6-bis（3,5-dimethyl-pyazole-1-yl）-1,2,4,5-tetrazine（BT）was synthesized by using triaminoguanidine hydrochloride and acetylacetone as raw materials,3,6-（pyazole-1-yl）-1,2,4,5-tetrazine was prepared by reacting BT with 1-H-pyazole.Five compounds were obtained by reacting BT or 3,6-（pyazole-1-yl）-1,2,4,5-tetrazine with semicarbazide hydrochloride,3,4-diamino-1,2,4-triazole hydrochloride and 3-hydrozino-4-amino-1,2,4-triazole di-hydrochloride respectively.The crystal structures of these compounds were obtained,of which six structures are not reported yet.The compounds were all characterized by elemental analysis,FT-IR and mass spectra,the decomposition property was also tested.（2）Four series of energetic complexes with the tetrazine compounds as ligands,Co,Ni,Cu,Fe as center metal,perchlorate as counter-anion were synthesized.All the complexes were characterized by using elemental analysis,FT-IR and mass spectra,so the molecular compositions were defined.（3）The decomposition and non-isothermal kinetics of complexes were researched by differential scanning calorimeter（DSC）,the first decomposition peaks of all the complexes are around 200℃,which indicates a relatively good thermal stability.[Fe（DSTz）₃]（ClO₄）₂ possesses the largest activation energy among the five Fe complexes,which indicates that it is the most stable when heated.[Fe（PHTz）₃]（ClO₄）₂ and[Fe（DHTz）₃]（ClO₄）₂ possess the lowest activation energy,and the highest laser sensitivities,so the laser initiation mechanism of the complexes may be thermal initiation.（4）To evaluate the application performances of the complexes,the friction and electronstatic sensitivities of all the complexes were tested,the impact sensitivity of Fe complexes was also tested,the results indicate that all the complexes are insensitive towards environment stimuli,the sensitivities of Cu complexes are higher than others.Fe complexes have sensitivities close to secondary explosives,which demonstrates that they possess good sensitivities.（5）UV-vis-NIR spectras of Fe complexes were examed and the absorption intensity of Fe complexes in 200-1200 nm was observed.The laser sensitivities of Fe complexes were tested.The laser device generates 808nm single pulse laser.The results show that[Fe（PHTz）₃]（ClO₄）₂and[Fe（DHTz）₃]（ClO₄）₂ possess the highest laser sensitivities,the lowest intiation energies of them are 18 and 30 mJ respectively,and the laser sensitivities of the complexes are positively correlated with the absorpotion intensity in 808 nm.[Fe（PHTz）₃]（ClO₄）₂and[Fe（DHTz）₃]（ClO₄）₂ possess very good laser sensitivities while they are insensitive towards mechanical and electronstatic stimuli,which strike a balance between reliability and safety,so they are laser intiation explosives with good performances.