The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation perform...The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.展开更多
In order to search for high energy density materials,various 4,8-dihydrodifurazano[3,4-b,e]pyrazine based energetic materials were designed.Density functional theory was employed to investigate the relationships betwe...In order to search for high energy density materials,various 4,8-dihydrodifurazano[3,4-b,e]pyrazine based energetic materials were designed.Density functional theory was employed to investigate the relationships between the structures and properties.The calculated results indicated that the properties of these designed compounds were influenced by the energetic groups and heterocyclic substituents.The-N3 energetic group was found to be the most effective substituent to improve the heats of formation of the designed compounds while the tetrazole ring/-C(NO_(2))_(3) group contributed much to the values of detonation properties.The analysis of bond orders and bond dissociation energies showed that the addition of-NHNH2,-NHNO_(2),-CH(NO_(2))_(3) and-C(NO_(2))_(3) groups would decrease the bond dissociation energies remarkably.Compounds A8,B8,C8,D8,E8,and F8 were finally screened as the potential candidates for high energy density materials since these compounds possess excellent detonation properties and acceptable thermal stabilities.Additionally,the electronic structures of the screened compounds were calculated.展开更多
A series of adamantyl nitrates have been theoretically studied from gas to solid to search for new po-tential high energy density compounds (HEDCs). The heats of formation (HOFs) for the 26 title com-pounds were calcu...A series of adamantyl nitrates have been theoretically studied from gas to solid to search for new po-tential high energy density compounds (HEDCs). The heats of formation (HOFs) for the 26 title com-pounds were calculated by designing isodesmic reactions at the B3LYP/6-31G level. It was found that the HOFs of the 26 isomers with the same number of —ONO2 groups (n) are not correlated well with the corresponding substituted positions. According to the obtained heats of detonation (Q),detonation velocities (D),and detonation pressures (P) using the Kamlet-Jacobs equations,it was found that when n=7～8,the adamantyl nitrates meet the criterion as an HEDC. The calculations on bond dissociation energies of O—N (EO—N) showed that the adamantyl nitrates with gemi —ONO2 always have the worst stability among the isomers,and all the adamantyl nitrates with gemi —ONO2 have similar stability. Due to the complexity of their structures,values of EO—N do not decrease with the increase of the substituent number n obviously,and the stability of adamantyl nitrates is not determined by only one structural parameter. Considering the stability requirement,only 1,2,4,6,8,9,10-adamantyl heptanitrate is recom-mended as a feasible HEDC. Molecular packing searching for 1,2,4,6,8,9,10-adamantyl heptanitrate among 7 most possible space groups (P21/c,P-1,P212121,P21,Pbca,C2/c,and Pna21) using Compass and Dreiding force fields showed that this compound tends to crystallize in P21/c. Ab initio periodic calculations on the electronic structure of the predicted packing showed that the O—NO2 bond is the trigger bond during thermolysis,which agrees with the result derived from the study of dissociation energies of O—N bonds.展开更多
At the B3PW91/6-311+G(d,p)//MP2/6-311+G(d,p)level,molecular densities,detonation velocities,and detonation pressures of nitroso substituted derivatives of azetidine with their thermal stabilities were investigated to ...At the B3PW91/6-311+G(d,p)//MP2/6-311+G(d,p)level,molecular densities,detonation velocities,and detonation pressures of nitroso substituted derivatives of azetidine with their thermal stabilities were investigated to look for high energy density compounds(HEDCs).It was found that the azetidine derivatives had high heat of formation(HOF)and large bond dissociation energy(BDE).Intramolecular hydrogen bonds were located in three molecules(1,4,and 5),and the molecular stability were improved markedly as well.For 5 and 6,the detonation performances(D=9.36km/s and 10.80km/s,P=44.42GPa and 60.70GPa,respectively)meet requirements as high energy density compounds.This work may provide basic information for further study of title compounds.展开更多
A series of derivatives of pyridazine were designed through substituting hydrogens on the pyridazine ring with nitro groups.To explore the thermal stability of the title molecules,heats of formation,bond dissociation ...A series of derivatives of pyridazine were designed through substituting hydrogens on the pyridazine ring with nitro groups.To explore the thermal stability of the title molecules,heats of formation,bond dissociation energies,and bond orders were calculated at the B3PW91/6-311+G(d,p)level.To confirm the potential usage as high energy density compounds,the detonation pressure and detonation velocity were predicted by using the empirical Kamlet-Jacobs(K-J)equation.Based on our calculated results,both thermal and kinetic stabilities of the title molecules are confirmed with good detonation characters.Especially,3,4,5-trinitropyridazide and 3,4,6-trinitropyridazide represent excellent detonation parameters better than 1,3,5-trinitro-1,3,5-triazacyclohexane(RDX)and are screened out as potential high energy density compounds.展开更多
基金supported by the Natural Science Foundation of Guizhou Province(QKJ[2014]2140 and QJTD[2012]052)
文摘The nitrate ester substitution derivatives of prismane were studied at the B3LYP/6-311G＊＊ level. The sublimation enthalpies and heats of formation in gas phase and solid state were calculated. The detonation performances were also predicted by using the famous Kamlet-Jacbos equation. Our calculated results show that introducing nitrate ester group into prismane is helpful to enhance its detonation properties. Stabilities were evaluated through the bond dissociation energies, bond order, characteristic heights（H50） and band gap calculations. The trigger bonds in the pyrolysis process of prismane derivatives were confirmed as O–ON2 bond. The BDEs of all compounds were large, so these prismane derivatives have excellent stability consistent with the results of H50 and band gap.
基金This work was supported by the National Natural Science Foundation of China(No.11602121)the Program for Scientific Research Innovation Team in Colleges and Universities of Ji’nan(No.2018GXRC006).
文摘In order to search for high energy density materials,various 4,8-dihydrodifurazano[3,4-b,e]pyrazine based energetic materials were designed.Density functional theory was employed to investigate the relationships between the structures and properties.The calculated results indicated that the properties of these designed compounds were influenced by the energetic groups and heterocyclic substituents.The-N3 energetic group was found to be the most effective substituent to improve the heats of formation of the designed compounds while the tetrazole ring/-C(NO_(2))_(3) group contributed much to the values of detonation properties.The analysis of bond orders and bond dissociation energies showed that the addition of-NHNH2,-NHNO_(2),-CH(NO_(2))_(3) and-C(NO_(2))_(3) groups would decrease the bond dissociation energies remarkably.Compounds A8,B8,C8,D8,E8,and F8 were finally screened as the potential candidates for high energy density materials since these compounds possess excellent detonation properties and acceptable thermal stabilities.Additionally,the electronic structures of the screened compounds were calculated.
基金the National Natural Science Foundation of China (Grant Nos. 10576016 and 10576030)the National 973 Project
文摘A series of adamantyl nitrates have been theoretically studied from gas to solid to search for new po-tential high energy density compounds (HEDCs). The heats of formation (HOFs) for the 26 title com-pounds were calculated by designing isodesmic reactions at the B3LYP/6-31G level. It was found that the HOFs of the 26 isomers with the same number of —ONO2 groups (n) are not correlated well with the corresponding substituted positions. According to the obtained heats of detonation (Q),detonation velocities (D),and detonation pressures (P) using the Kamlet-Jacobs equations,it was found that when n=7～8,the adamantyl nitrates meet the criterion as an HEDC. The calculations on bond dissociation energies of O—N (EO—N) showed that the adamantyl nitrates with gemi —ONO2 always have the worst stability among the isomers,and all the adamantyl nitrates with gemi —ONO2 have similar stability. Due to the complexity of their structures,values of EO—N do not decrease with the increase of the substituent number n obviously,and the stability of adamantyl nitrates is not determined by only one structural parameter. Considering the stability requirement,only 1,2,4,6,8,9,10-adamantyl heptanitrate is recom-mended as a feasible HEDC. Molecular packing searching for 1,2,4,6,8,9,10-adamantyl heptanitrate among 7 most possible space groups (P21/c,P-1,P212121,P21,Pbca,C2/c,and Pna21) using Compass and Dreiding force fields showed that this compound tends to crystallize in P21/c. Ab initio periodic calculations on the electronic structure of the predicted packing showed that the O—NO2 bond is the trigger bond during thermolysis,which agrees with the result derived from the study of dissociation energies of O—N bonds.
基金supported by the Natural Science Foundation of Guizhou Province(Nos.QKHPTRC[2018]5778-09 and QKHJC[2020]1Y038)the Natural Science Foundation of Guizhou Education University(Nos.14BS017 and 2019ZD001).
文摘At the B3PW91/6-311+G(d,p)//MP2/6-311+G(d,p)level,molecular densities,detonation velocities,and detonation pressures of nitroso substituted derivatives of azetidine with their thermal stabilities were investigated to look for high energy density compounds(HEDCs).It was found that the azetidine derivatives had high heat of formation(HOF)and large bond dissociation energy(BDE).Intramolecular hydrogen bonds were located in three molecules(1,4,and 5),and the molecular stability were improved markedly as well.For 5 and 6,the detonation performances(D=9.36km/s and 10.80km/s,P=44.42GPa and 60.70GPa,respectively)meet requirements as high energy density compounds.This work may provide basic information for further study of title compounds.
基金supported by the Foundation of Natural Science of Guizhou Education University(No.14BS017)。
文摘A series of derivatives of pyridazine were designed through substituting hydrogens on the pyridazine ring with nitro groups.To explore the thermal stability of the title molecules,heats of formation,bond dissociation energies,and bond orders were calculated at the B3PW91/6-311+G(d,p)level.To confirm the potential usage as high energy density compounds,the detonation pressure and detonation velocity were predicted by using the empirical Kamlet-Jacobs(K-J)equation.Based on our calculated results,both thermal and kinetic stabilities of the title molecules are confirmed with good detonation characters.Especially,3,4,5-trinitropyridazide and 3,4,6-trinitropyridazide represent excellent detonation parameters better than 1,3,5-trinitro-1,3,5-triazacyclohexane(RDX)and are screened out as potential high energy density compounds.
