Studies On Explosive Sensitivity Of Nitrotriazole Using Ab Initio And DFT Computational Methods

Triazole is a kind of heterocyclic compounds with high contents of nitrogen. Nitrotriazolederivatives have low carbon and hydrogen, large densities, thermal stability, they are potentialinsensitive high explosive （IHE）, so nitrotriazole derivatives with1,2,3-triazole、1,2,4-triazolearoused people’s great attention.The changes of bond dissociation energy（BDE） in the C–NO₂bond and nitro groupcharge upon the formation of the intermolecular hydrogen-bonding interaction between HFand the nitro group of14kinds of nitrotriazoles or methyl derivatives were investigated usingthe B3LYP and MP2（full） methods with the6-311++G^**,6-311++G（2df,2p） andaug-cc-pVTZ basis sets. The BDE of the trigger was improved, the strength of the C–NO₂bond was enhanced and the charge of nitro group turned more negative in complex incomparison with those in isolated nitrotriazole molecule. Electron density shifts analyses alsoreached the same conclusion. At the same time, we found the increment of the C–NO₂bonddissociation energies correlated well with the intermolecular H-bonding interaction energies.The changes of the bond dissociation energy of the C–NO₂trigger bond and nitro groupcharge upon the formation of the molecule-cation interaction between Na⁺and the nitro groupof14kinds of nitrotriazoles or its methyl derivatives have been investigated using the B3LYPand MP2（full） methods with the6-311++G^**,6-311++G（2df,2p） and aug-cc-pVTZ basis sets.The length of the trigger bond is decreased, the BDE is improved, the strength of it enhancedand the explosive sensitivity is reduced upon the formation of molecule-cation interaction.The analyses of AIM and electron density shifts also prove this. Meanwhile, the increment ofthe trigger bond dissociation energy in comparison with the monomer （ΔBDE） correlates wellwith the molecule-cation interaction energy.The bond dissociation energy of the N–NO₂trigger bond of14kinds of nitrotriazolemonomer, and the change of the BDE of N–NO₂trigger bond upon the formation of themolecule-cation interaction between the monomer and cation （Na⁺） and hydrogen-bondinginteraction between that and HF have been systematically investigated using the B3LYP andMP2（full） methods with the6-311++G^**，6-311++G（2df,2p） and aug-cc-pVTZ basis sets. The length of the trigger is shorter, the density of it increases and the bond dissociatioinenergy is larger in two types of complexes. The ΔBDE of the N–NO₂bond in the Na+complexis far greater than that in the corresponding HF system. Thus, introducing cation into thestructure of the nitrotriazole and its derivatives might be more efficacious to reduce explosivesensitivity than the formation of the intermolecular hydrogen-bonded complex.In summary, this dissertation has not only provided a large amount of basic data abouttriazole heterocyclic compounds, but also summed up some valuable rules which are helpfulto the further theoretical study and molecular design of these kinds of IHE.