Theoretical study of energetic carbon-oxidized triazole and tetrazole derivatives

2015 ◽  
Vol 93 (3) ◽  
pp. 368-374 ◽  
Author(s):  
Guolin Xiong ◽  
Zhichao Liu ◽  
Qiong Wu ◽  
Weihua Zhu ◽  
Heming Xiao

We investigated the heat of formation, density, thermal stability, and detonation properties of a series of carbon-oxidized triazole and tetrazole derivatives substituted by –NH2 and –NO2 groups using density functional theory. It is found that their properties are associated with the numbers of substituents and substitution positions in the parent ring. The results show that the –NO2 group is an effective structural unit for enhancing their detonation performance. It also indicates that the substitution positions play a very important role in increasing the heat of formation values of the derivatives. An analysis of impact sensitivity (h50) indicates that incorporating the –NH2 groups into the parent ring increases their thermal stability. Considering the detonation performance and thermal stability, seven of the designed compounds may be regarded as potential high-energy compounds. These results provide basic information for the molecular design of novel high-energy compounds.

2013 ◽  
Vol 91 (6) ◽  
pp. 369-374 ◽  
Author(s):  
Xiao-Hong Li ◽  
Xian-Zhou Zhang

A newly designed polynitro cage compound with a framework of hexanitrohexaazaisowurtzitane (HNIW) was investigated by density functional theory (DFT) calculations. The molecular structure was optimized at the B3LYP/6-31G** level. IR spectrum, heat of formation (HOF), and thermodynamic properties were also predicted. The detonation velocity and pressure were evaluated by using the Kamlet–Jacobs equations, based on the theoretical density and condensed HOF. The bond dissociation energies (BDEs) and bond orders for the weakest bonds were analyzed to investigate the thermal stability of the title compound. The results show that the first step of pyrolysis is the rupture of the N8–NO2 bond. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with the following lattice parameters: Z = 2, a = 11.10 Å, b = 15.15 Å, c = 10.77 Å, ρ = 1.872 g cm−3. The designed compound has high thermal stability and good detonation properties, and is a promising high-energy-density compound.


2021 ◽  
Author(s):  
Wenxin Xia ◽  
Renfa Zhang ◽  
Xiaosong Xu ◽  
Congming Ma ◽  
Peng Ma ◽  
...  

Abstract In this study, 32 energetic compounds were designed using oxadiazoles (1,2,5-oxadiazole, 1,3,4-oxadiazole) as the parent by inserting different groups as well as changing the bridge between the parent. These compounds had high-density and excellent detonation properties. The electrostatic potentials of the designed compounds were analyzed using density functional theory (DFT). The structure, heat of formation (HOF), density, detonation performances (detonation pressure P , detonation velocity D , detonation heat Q ), and thermal stability of each compound were systematically studied based on molecular dynamics. The results showed that the -N 3 group has the greatest improvement in HOF. For the detonation performances, the directly linked, -N=N-, -NH-NH- were beneficial when used as a bridge between 1,2,5-oxadiazole and 1,3,4-oxadiazole, and it can also be found that bridge changing had little effect on the trend of detonation performance, while energetic groups changing influenced differently. The designed compounds (except for A2 , B2 , B4 ) all had higher detonation properties than TNT, A6 ( D = 9.41 km s -1 , P = 41.86 GPa, Q = 1572.251 cal g -1 ) was the highest, followed D6 had poorer performance ( D = 8.96 km s -1 , P = 37.46 GPa, Q = 1354.51 cal g -1 ).


2014 ◽  
Vol 1058 ◽  
pp. 122-126 ◽  
Author(s):  
Hua Zhou ◽  
Zhong Liang Ma ◽  
Jia Hu Guo ◽  
Jian Long Wang

Computations by density functional theory (DFT) method were performed on a series of di-s-tetrazine derivatives with different substituents and linkages. The heat of formation (HOF) was predicted by designed isodesmic reaction. The results illustrated that introductions group –N3or –N=N– could augment the HOF extremely. The crystal structures were obtained by molecular mechanics methods with dreiding force field. Detonation performance was evaluated by using the Kamlet-Jacobs based on the calculated density and HOF. It was found that –ONO2, –NF2, –NH–NH– and –N=N– groups were effective to enhance the detonation performance of these derivatives. Seven compounds were screened as the potential candidates for high energy density materials.


Author(s):  
Zhibin Qi ◽  
Yong Lu ◽  
Rui-Jun Gou ◽  
Shu-Hai Zhang

In order to study the properties of new energetic compounds formed by introducing nitroazoles into 2,4,6-trinitrobezene, the density, heat of formation and detonation properties of 36 nitro-1-(2,4,6-trinitrobenzene)-1H-azoles energetic compounds are studied by density functional theory, and their stability and melting point are predicted. The results show that most of target compounds have good detonation properties and stability. And it is found that nitro-1-(2,4,6-Trinitrophenyl)-1H-pyrrole compounds and nitro-1-(2,4,6-trinitropenyl)-1H-Imidazole compounds have good thermal stability, and their weakest bond is C-NO2 bond, the bond dissociation energy of the weakest bond is 222 kJ mol-1-238 kJ mol-1 and close to TNT (235 kJ mol-1). The weakest bond of the other compounds may be the C-NO2 bond or the N-N bond, and the strength of the N-N bond is related to the nitro group on azole ring.


2013 ◽  
Vol 12 (01) ◽  
pp. 1250095
Author(s):  
GUI-XIANG WANG ◽  
XUE-DONG GONG ◽  
YAN LIU ◽  
HE-MING XIAO

The cyano (–CN), isocyano (–NC), nitramine (–NNO2), and nitrate (–ONO2) derivatives of HNS has been studied in this work at the B3LYP/6-31G* level of density functional theory. Their IR spectra were predicted and assigned by vibrational analysis. Based on the frequencies scaled by 0.96 and the principle of statistic thermodynamics, the thermodynamic functions were evaluated. It is found that the thermodynamic functions linearly increase with the number of – CN , – NC , – NNO2 , and – ONO2 groups, as well as the temperature. The contribution of various substitutents to the thermodynamic functions has the order of – ONO2 > –NNO2 > –NC > –CN . Detonation properties were evaluated using the modified Kamlet–Jacobs equations based on the calculated densities and heats of formation. Compared with the commonly used explosives (RDX and HMX), 3,3′,5-trinitramine-2,2′,4,4′,6,6′-Hexanitrostilbene, 3,3′,5,5′-tetranitramine-2,2′, 4,4′,6,6′-Hexanitrostilbene, 3,3′,5-trinitrate-2,2′,4,4′,6,6′-Hexanitrostilbene, and 3,3′,5,5′-tetranitrate-2,2′, 4,4′,6,6′-Hexanitrostilbene have better detonation performance and may be potential candidates of high energy density compounds.


Author(s):  
Lian Zeng ◽  
Yuhe Jiang ◽  
Jinting Wu ◽  
Hongbo Li ◽  
Jianguo Zhang

Abstract: In the present work, the geometric structures, the frontier molecular orbitals and the enthalpy of formation (HOF) of thirty six 1, 2, 4, 5-tetrazine derivatives (FTT) were systematically studied by using the B3LYP/6-311+G* method of density functional theory. Meanwhile, we also predicted the stability, detonation properties and thermodynamic properties of all FTT compounds. Results showed that all compounds have superior enthalpy of formation far exceeding that of common explosives RDX and HMX, ranging from 859kJ·mol-1-1532kJ·mol-1. In addition, the detonation performance (Q = 1426cal·g-1 -1804cal·g-1; P = 29.54GPa - 41.84GPa; D = 8.02km·s-1 - 9.53km·s-1), which is superior to TATB and TNT. It is also concluded that the introduction of coordination oxygen on the tetrazine ring can improve the HOF, density and detonation performance of the title compound, and -NH-NH- bridge and -NHNO2 group are also the perfect combination to increase these values. In view of stability, because of the fascinating performance of D3 (ρ =1.89g·cm-3; D = 9.38km·s-1; P = 40.13GPa),E3(ρ = 1.87g·cm-3; D = 9.19km·s-1; P = 38.35GPa), F1 (ρ = 1.87g·cm-3; D = 9.42km·s-1; P = 40.23GPa) and F3 (ρ= 1.92g·cm-3; D = 9.53km·s-1; P = 41.84GPa), makes them very attractive to be chosen as HEDMs.


2013 ◽  
Vol 91 (12) ◽  
pp. 1233-1242 ◽  
Author(s):  
Fang Xiang ◽  
Qiong Wu ◽  
Weihua Zhu ◽  
Heming Xiao

Density functional theory and volume-based thermodynamics calculations have been performed to study the crystal densities, heats of formation, energetic properties, thermodynamics of formation, and impact sensitivity for a series of heterocycle-functionalized tetrazolate- and tetrazolate1-oxide-based dianionic salts. The results show that the hydroxylammonium cation is better than the tetrazolium cation for increasing the densities and detonation performance of the tetrazolate dianionic salts. The salts containing series B (tetrazolate-1-oxide) have larger densities and detonation performance than corresponding ones containing series A (tetrazolate) with the same cation. Incorporating a zwitterionic N-oxide into the nitrogen system is helpful for increasing its density and detonation performance for each salt series, but it is not favorable for improving its heat of formation. The salt including the tetrazine-dioxide conjugated with two tetrazolide exhibits the best energetic performance. The salts containing the tetrazolium cation could be possibly synthesized by the proposed reactions. Some of the salts with the cation hydroxylammonium show lower impact sensitivity than RDX or HMX.


2019 ◽  
Vol 97 (2) ◽  
pp. 86-93 ◽  
Author(s):  
Yong Pan ◽  
Weihua Zhu ◽  
Heming Xiao

A new family of azaoxaadamantane cage compounds were firstly designed by introducing the oxygen atom into hexanitrohexaazaoxaadmantane (HNHAA) to replace the N–NO2 group. Their properties including heats of formation (HOFs), detonation properties, strain energies, thermal stability, and sensitivity were extensively studied by using density functional theory. All of the title compounds exhibit surprisingly high density (ρ > 2.01 g/cm3) and excellent detonation properties (detonation velocity (D) > 9.29 km/s and detonation pressure (P) > 40.80 GPa). In particular, B (4,8,9,10-tetraazadioxaadamantane) and C (6,8,9,10-tetraazadioxaadamantane) have a remarkably high D and P values (9.70 km/s and 44.45 GPa, respectively), which are higher than that of HNHAA or CL-20. All of the title compound have higher thermal stability and lower sensitivity (h50 > 19.58 cm) compared with the parent compound HNHAA. Three triazatrioxaadamantane cage compounds, D (6,8,9-triazatrioxaadamantane), E (6,8,10-triazatrioxaadamantane), and F (8,9,10-triazatrioxaadamantane), are expected to be relatively insensitive explosives. All of the title compounds exhibit a combination of high denotation properties, good thermal stability, and low insensitivity.


2016 ◽  
Vol 94 (8) ◽  
pp. 667-673 ◽  
Author(s):  
Dong Xiang ◽  
Hao Chen ◽  
Weihua Zhu ◽  
Heming Xiao

A design strategy that including N atoms, N-oxides, and nitro groups into a cage azaadamantane at the same time was used to design 10 polyazaoxyadamantanes (PAOAs) and eight polynitroazaoxyadamantanes (PNTAOAs). First, four stable azaadamantanes were built by replacing the tertiary C atoms of an adamantane with N atoms. Then, 10 PAOAs were designed by introducing one to four N-oxides into the four azaadamantanes. After that, eight PNTAOAs were formed when the H atoms of four N-oxide-substituted azaadamantanes were replaced with different numbers of nitro groups. Finally, their heats of formation, densities, detonation properties, and impact sensitivity were estimated by using density functional theory. Among the eight PNTAOAs, seven compounds had better detonation performances than CL-20, the outstanding, novel, high-energy, and relatively insensitive cage explosive. Two compounds had higher detonation performance and lower sensitivity than CL-20 and HMX, suggesting that their overall performances are outstanding and they may be considered as the potential candidate of high-energy explosives.


2008 ◽  
Vol 15 (03) ◽  
pp. 249-259 ◽  
Author(s):  
PATRICIA G. BELELLI ◽  
NORBERTO J. CASTELLANI

The addition of hydrogen to the carbon–carbon double bond of 2-butenes adsorbed on Pd (111) was studied within the density functional theory (DFT) and using a periodic slab model. For that purpose, the Horiuti–Polanyi mechanisms for both complete hydrogenation and isomerization were considered. The hydrogenation of cis and trans-2-butene to produce butane proceeds via the formation of eclipsed and staggered-2-butyl intermediates, respectively. In both cases, a relatively high energy barrier to produce the half-hydrogenated intermediate makes the first hydrogen addition the slowest step of the reaction. The competitive production of trans-2-butene from cis-2-butene requires the conversion from the eclipsed-2-butyl to the staggered-2-butyl isomer. As the corresponding energy barrier is relatively small and because the first of these isomers is less stable than the second, an easy conversion is predicted.


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