Studies On Synthesis,Characterization And Properties Of Tetrazol-5-yl Energetic Compounds

Bistetrazoles play a significant role in the research of the novel High-energy density materials?HMDMs?,due to high formation enthalpy,low evaporation pressure and high stability.Meanwhile bistetrazoles have potential application prospects in the field of gas generant,propellent,pyrotechnic composition,and so on.Therefore,bistetrazole energetic compounds have been systematically investigated including high-nitrogen iron salts,metal complex and the energetic modifications of bistetrazoles.The main contents of this paper are as followings:1.The ammonium salt?1?and the hydroxylammonium salt?2?of bis?5-tetrazolyl?methanone oxime?H₂BTO?were prepared and their crystal structures were first characterized,which contributed to investigate the relationship between structures and properties.?CN₃H₆?[Li?HBTO??H₂O?₂]?3?with Li⁺as the center metal was synthesized and characterized,which provided experimental evidences for universality of anionic coordination model.In addition,the novel nitrogen-rich polymers[Na?HBTO??H₂O?₂·2H₂O]_n?4?,?NH₃OH?₂[Na₂?BTO?₂?H₂O?₄·H₂O]_n?5?,?NH₃OH?[Na?BTO??H₂O?₂]_n?6?,were synthesized by using Na⁺as the central ion for the first time.The oxime group of H₂BTO exhibits variable coordination and deprotonation patterns which may be significant for future studies of other metal polymer based on H₂BTO.Furthermore,[Ba?BTO?·?H₂O?₃]_n?7?have been synthesized,results showed that H₂BTO is coordinated by six-chelate to form three stable chelated ring,and the whole molecule exhibited 3D-MOFs structure.The existence of oxime group of H₂BTO exhibited variable coordination and deprotonation patterns.Moreover,results displayed that they had high thermal stability and heat of combustion,such as compound 7?decomposition temperature is greater than 340^oC?and compound 5(heat of combustion is-9691.2kJ?kg^-1).2.The compound 9 was synthesis with di?1H-tetrazol-5-yl?methane as raw material,KMnO₄ as oxidizer.Additionaly,di?1H-tetrazol-5-yl?methanone?10?was synthesised through the acidification of hydrochloric.Results revealed that the introduction of the carbonyl group improves the density as well as the improvement of oxygen balance.3.Di?5-tetrazolyl?-methanediol?11?was synthesised,which can be stable in the solid state.The results displayed that the crystal water enhances the stability of the gem-diol compound through the hydrogen bond interaction,which provided an important experimental basis for the further study of chemical properties of gem-diol compounds.4.It was found for the first time that compound 11 was able to dehydrate to bis?5-tetrazolyl?methanone?10?,which could be transformed between the crystal states.5.Compounds C₃H₄N₁₀?12?,C₃H₄N₁₀·H₂O?13?,(C₄H₅N₁₂)?CN₄H₇?·H₂O?14?,and C₄H₈N₁₄·2H₂O?15?were prepared by condensation of compound 9with hydrazine,diaminoguanidine and triaminoguanidine hydrochloride.Among them,compounds 12 and 13 have good application prospects in the field of energetic materials.The analytical results of compounds 14 and 15show that the synthesis method not only can improve the number of amino-modification sites but also increasing the nitrogen content of the target compounds.The synthesis can be used for the design of novel tetrazole compounds and providing a new technical approach for the high energy density materials.