Study Of Synthesis And Properties Of Hydroxytetrazole Energetic Complexes

As an important material closely related to human production and life,energetic materials are indispensable in many fields.In order to obtain new energy-containing materials that are high in energy,low in sensitivity and green,many researchers have carried out extensive research.Hydroxytetrazole,as a nitrogen rich heterocyclic compound,has high enthalpy of production,good oxygen balance and thermal stability and environmentally friendly decomposition products.A large number of literatures have shown that the formation of energetic metal complexes by combining high-energy nitrogen rich compounds with metal ions is an important method to obtain new energetic materials with excellent comprehensive properties.At the same time,Hydroxytetrazole as a ligand has rich and varied coordination sites,which provides the basis for the construction of energetic complexes with rich structure.Based on this,two lead complexes,two cobalt complexes,two nickel complexes,two zinc complexes and one manganese complex,were obtained by controlling hydrothermal conditions with Hydroxytetrazole as a high energy ligand.(1)Hydroxytetrazole was synthesized from ethyl chlorooxime acetate,and its structure was determined by single crystal diffraction and nuclear magnetic carbon spectroscopy.Due to the use of high reagents such as acetyl chloride and benzene in the original literature,and the harsh conditions and low reaction efficiency of the original route,we optimized the route of the literature,avoiding the use of high reagents.The yield was increased from 22%to 90%,which provided raw material guarantee for follow-up work.The results of thermal analysis show that the melting point of hydroxytetrazole is 433 K,the decomposition peak temperature is 472.9 K,and the activation energy is 183.6 k J mol^-1.It is a high energy nitrogen rich ligand with good thermal stability.(2)Seven metal complexes were synthesized by hydrothermal reaction of hydroxytetrazole with lead,cobalt,nickel,zinc and manganese ions,respectively,and the structures of the complexes were analysed by single crystal XRD.Due to the difference of coordination anions,two kinds of lead complexes[Pb(OH-TZ)₂]_n and[Pb(OH-TZ)(NO₃)]_nwere obtained.Both lead complexes have high density,and their structures are stable The density of[Pb(OH-TZ)(NO₃)]_n is as high as 4.154 g cm^-3.Due to the difference of the N atoms involved in the coordination,we obtained two cobalt complexes,in which[CO(OH-TZ)₂(H₂O)₂]_n has less coordination water and higher density than[CO(OH-TZ)₂(H₂O)₂]_n.The coordination position of[CO(OH-TZ)₂(H₂O)₂]_n is the same as that of Ni and Zn complexes,but the coordination position of N in Mn complexes is different from that mentioned above.The rich and varied complex structure also proves that 1-hydroxytetrazole is an excellent ligand for constructing energetic metal complexes.(3)Through DSC,BAM sensitivity instrument and MS(Materials Studio)DMOL3module in studio software evaluated the thermal stability,mechanical sensitivity and detonation performance of the complexes.All the complexes have excellent thermal stability(T_dec>200?);except lead complexes are sensitive to mechanical stimulation,other complexes show sudden sensitivity to mechanical stimulation;theoretical calculation shows that the detonation velocity and detonation pressure of these complexes are equivalent to HMX and RDX,among which is the most unsensitive[CO(OH-TZ)₂(H₂O)₂]_n has the same detonation performance(detonation velocity 9.3 km s^-1,detonation pressure 42.29 Gpa)as CL-20 under the condition of mechanical stimulation(IS=30 J,FS>360 N).The response process of lead complexes to laser was studied by femtosecond laser and high-speed camera.Both lead complexes are sensitive to laser,and the response process is a typical detonation process.Due to their strong work ability,they can be used as potential laser initiators.The catalytic effect of the complex on the thermal decomposition of AP was studied by DTA.The addition of 10 wt%[CO(OH-TZ)₂(H₂O)₄]_n made the high temperature decomposition peak of AP advance 115 K and the activation energy decrease 66 k J mol^-1,which had a good catalytic effect on the thermal decomposition of AP.