Theoretic Studies Of The Structure And Properties Of High-Energy Nitrogen-Rich Ionic Salts

Density functional theory (DFT), second-order Moller-Plesset perturbation theory (MP2), and volume-based thermodynamics (VBT) methods were used to study the densities, heats of formation, detonation properties, impact sensitivities, and thermodynamics of formation of different series of nitrogen-rich energetic furazan-, tetrazole-, and tetrazine-based ionic salts in this thesis. The geometric optimization and frequency analyses of the title ions were carried out at the B3LYP/6-31++G*level, and single point energies were calculated at the MP2/6-311++G**level. The effects of different substituents, heterocycles, bridges, and the combination of cations and anions on in the properties of the title salts were investigated. The semiempirical Kamlet-Jacobs equations were used to predict the detonation properties of the energetic salts. To determine the possibility of the ionic salts’formation, the Born-Haber Cycles for the formation of the salts were established to predict the changes of their Gibbs free energy. By comparing with commonly used explosives RDX and HMX, the potential candidates with excellent performance were selected. This study is organized as follows:1. A series of5-nitroiminotetrazolate-based ionic salts were designed in this part. The effects of-NH2,-NO2,-NF2,-N3, and-C(NO2)3groups on the properties of the salts were investigated. The effects of the combination of different kinds of energetic cations and5-nitroiminotetrazolate-based anions on the salts were analyzed. The effects of5-nitroiminotetrazolate-based anions with one negative charge and two negative charges on the properties of the salts were compared.2. The properties of the salts composed of5-dinitromethyltetrazolate-based anions and several cations were studied. The effects of energetic substituents and different substitution positions of the same substituent on the properties of the salts were discussed. The effects of5-dinitromethyltetrazolate-based anions with one negative charge and two negative charges on the properties of the salts were analyzed.3. A series of heterocycle-functionalized tetrazolate-and tetrazolatel-oxide-based dianionic salts were investigated in this part. The effects of different kinds of heterocycles on the properties of the salts were studied.The effects of incorporating zwitterionic N-oxide into the heterocycle compounds on the properties of the salts waere discussed.4. The energetic salts composed of heterocycle-functionalized (furazan, tetrazole, and tetrazine) nitraminofurazanate-based anions and triaminoguanidinium were studied in this part. The effects of oxygen-containing energetic groups-NO2and-C(NO2)3on the properties of the salts were discussed. The effects of nitrogen bridges (-NH-,-NH-NH-,-N=N-, or-N=N-) on the properties of the salts were also analyzed.