Design And Properties Of Furazan Multicomponent Heterocyclic Energetic Compounds

Furazan energetic compounds are the focus of research because of their high density,good thermal stability and safety.In order to explore a new type of high energy density materials（HEDM）,nitrogen-rich furazan rings are the main research objects in this paper.The detonation performance of the compound was improved by introducing substituent groups.Three furazan derivatives have been systematically studied by DFT-B3LYP/6-311+G*method,and their density,enthalpy of formation,detonation velocity,detonation pressure,and impact sensitivity have been calculated.The main content is divided into the following three aspects:（1）Design and performance study of furazan-linked 1,2,4-triazole:Furazan and1,2,4-triazole were linked together to design eight compounds called the Tz IMFD series.The Tz IMFD series compounds have a density slightly higher than RDX(ρ=1.81-1.90 g·cm^-3),and higher detonation performance,impact sensitivity slightly better than RDX and good stability.The thermodynamic properties of all compounds showed an upward trend with increasing temperature.Among them,Compounds T1 and T7 possess both high density(T1:ρ=1.88 g·cm^-3;T7:ρ=1.90 g·cm^-3)and good detonation performance(T1:D=8.98 km·s^-1,P=36.73 Gpa;T7:D=9.17 km·s^-1,P=38.51 GPa),which may be a candidate for HEDM.（2）Design and properties of tetrazine bridged monofurazan:By bridging the tetrazine,furazan and tetrazole rings,thirty-six Tz BMFD compounds were composed by permutations with different substituents.This series of compounds has a positive enthalpy of formation much larger than that of the traditional compound HMX(102 k J·mol^-1).The influence of different bridges on HOF is arranged as follows:-NH-NH->-NH₂->-CH₂-.Among them,twenty-three compounds have excellent stability and bond dissociation energy BDE greater than 120 k J·mol^-1.All thermodynamic properties including heat capacity Cp,molar entropy Sm and molar enthalpy Hm increased with increasing temperature.Taking sensitivity into consideration,compounds D3,E3,F1 and F3 are expected to be high energy density materials due to their high densities(ρ=1.87-1.92 g·cm^-3)and excellent detonation performance(D=9.19-9.52 km·s^-1,P=38.35-41.83 GPa).（3）Design and properties of tetrazolone bridged difurazan:To BDFD series compounds are obtained by bridging the organic combination of tetrazolone and two furazan molecules,and further introducing different energetic groups,with a total of thirty-two species.This series of compounds have excellent positive enthalpies of formation far superior to conventional explosives,which lays the foundation for good detonation performance.The Q of twenty-nine compounds was better than that of RDX(1591 cal·g^-1),D of twenty-three compounds was higher than that of HMX(9.10 km·s^-1)and P of eighteen compounds was better than that of HMX（39.00 GPa）.All the title compounds except SG2 were stable.The increase of thermodynamic properties Cp gradually decreased with the increase of temperature,the increase of Sm remained basically unchanged,and the increase of Hm gradually increased.Finally,compounds SA4,SB1,SB2,SB4,SC4,SD4,SF4,SH1 and SH2 with good balance between properties and stability were screened as potential replacement for novel HEDM and provide theoretical basis for further research.