scholarly journals Theoretical calculation of nitro-1-(2,4,6-trinitrophenyl)-1H-azoles energetic compounds

2022 ◽  
Author(s):  
Zhibin Qi ◽  
Yong Lu ◽  
Rui-Jun Gou ◽  
Shu-Hai Zhang
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
Heat Of Formation ◽  
The Other ◽  
Detonation Properties ◽  
Energetic Compounds ◽  
Functional Theory ◽  
Good Thermal Stability ◽  
Azole Ring ◽  
Imidazole Compounds

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.

scholarly journals Theoretical studies of novel high energy density materials based on oxadiazoles

2021 ◽  
Author(s):  
Wenxin Xia ◽  
Renfa Zhang ◽  
Xiaosong Xu ◽  
Congming Ma ◽  
Peng Ma ◽  
...  
Keyword(s):  
Density Functional ◽  
High Energy ◽  
Heat Of Formation ◽  
High Energy Density ◽  
Detonation Properties ◽  
Detonation Pressure ◽  
Energetic Compounds ◽  
Functional Theory ◽  
High Energy Density Materials ◽  
Thermal Stability Of

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 ).

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
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
Theoretical Study ◽  
Molecular Design ◽  
High Energy ◽  
Heat Of Formation ◽  
Detonation Performance ◽  
Detonation Properties ◽  
Functional Theory ◽  
Tetrazole Derivatives

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.

Computational studies on a high density cage compound hexanitrohexaazaisowurtzitane derivative

2013 ◽  
Vol 91 (6) ◽  
pp. 369-374 ◽  
Author(s):  
Xiao-Hong Li ◽  
Xian-Zhou Zhang
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
High Energy ◽  
Heat Of Formation ◽  
High Energy Density ◽  
Detonation Properties ◽  
Functional Theory ◽  
Dissociation Energies ◽  
Cage Compound ◽  
Detonation Velocity And Pressure

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.

scholarly journals Nitramine Derivatives of NTO - A DFT Study

2019 ◽  
pp. 45-63 ◽  
Author(s):  
Lemi Türker
Keyword(s):  
Thermal Stability ◽  
Density Functional Theory ◽  
Molecular Orbital ◽  
Density Functional ◽  
Dft Study ◽  
Chemical Sensitivity ◽  
Functional Theory ◽  
Good Thermal Stability ◽  
Derivatives Of

NTO is a nitrotriazole type explosive having good thermal stability and low chemical sensitivity. It is relatively insensitive to impact and shock. In the present study, nitramine derivatives of NTO are considered within the constraints of density functional theory at the level of B3LYP/6-31+G(d). The stabilities, some geometrical, physicochemical, and some molecular orbital characteristics etc., of the structures are considered. The calculated IR and UV-VIS spectra are presented and discussed.

scholarly journals Screening for energetic compounds based on 1,3-dinitrohexahydropyrimidine skeleton and 5-various explosopheres: molecular design and computational study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Binghui Duan ◽  
Ning Liu ◽  
Xianming Lu ◽  
Hongchang Mo ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Energetic Materials ◽  
Molecular Design ◽  
Computational Study ◽  
Impact Sensitivity ◽  
Detonation Properties ◽  
Detonation Pressure ◽  
Energetic Compounds ◽  
Good Thermal Stability ◽  
Energetic Performance

Abstract In this paper, twelve 1,3-dinitrohexahydropyrimidine-based energetic compounds were designed by introducing various explosopheres into hexahydropyrimidine skeleton. Their geometric and electronic structures, heats of formation (HOFs), energetic performance, thermal stability and impact sensitivity were discussed. It is found that the incorporation of electron-withdrawing groups (–NO2, –NHNO2, –N3, –CH(NO2)2, –CF(NO2)2, –C(NO2)3) improves HOFs of the derivatives and all the substituents contribute to enhancing the densities and detonation properties (D, P) of the title compounds. Therein, the substitution of –C(NO2)3 features the best energetic performance with detonation velocity of 9.40 km s−1 and detonation pressure of 40.20 GPa. An analysis of the bond dissociation energies suggests that N–NO2 bond may be the initial site in the thermal decompositions for most of the derivatives. Besides, –ONO2 and –NF2 derivatives stand out with lower impact sensitivity. Characters with striking detonation properties (D = 8.62 km s−1, P = 35.08 GPa; D = 8.81 km s−1, P = 34.88 GPa), good thermal stability, and acceptable impact sensitivity (characteristic height H50 over 34 cm) lead novel compounds 5,5-difluoramine-1,3-dinitrohexahydropyrimidine (K) and 5-fluoro-1,3,5-trinitrohexahydropyrimidine (L) to be very promising energetic materials. This work provides the theoretical molecular design and a reasonable synthetic route of L for further experimental synthesis and testing.

scholarly journals Calculating Heat of Formation Values of Energetic Compounds: A Comparative Study

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Michael S. Elioff ◽  
Jordan Hoy ◽  
John A. Bumpus
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Density Functional ◽  
Heat Of Formation ◽  
Semiempirical Methods ◽  
Group Contribution Method ◽  
Energetic Compounds ◽  
Functional Theory ◽  
Test Set ◽  
Experimental Reference

Heat of formation is one of several important parameters used to assess the performance of energetic compounds. We evaluated the ability of six different methods to accurately calculate gas-phase heat of formation (ΔfH298,go) values for a test set of 45 nitrogen-containing energetic compounds. Density functional theory coupled with the use of isodesmic or other balanced equations yielded calculated results in which 82% (37 of 45) of the ΔfH298,go values were within ±2.0 kcal/mol of the most recently recommended experimental/reference values available. This was compared to a procedure using density functional theory (DFT) coupled with an atom and group contribution method in which 51% (23 of 45) of the ΔfH298,go values were within ±2.0 kcal/mol of these values. The T1 procedure and Benson’s group additivity method yielded results in which 51% (23 of 45) and 64% (23 of 36) of the ΔfH298,go values, respectively, were within ±2.0 kcal/mol of these values. We also compared two relatively new semiempirical approaches (PM7 and RM1) with regard to their ability to accurately calculate ΔfH298,go. Although semiempirical methods continue to improve, they were found to be less accurate than the other approaches for the test set used in this investigation.

scholarly journals Theoretical design of high-nitrogen energetic molecules: Performance prediction of pentazole-based derivatives

2021 ◽  
Author(s):  
Hao-Ran Wang ◽  
Chong Zhang ◽  
Cheng-Guo Sun ◽  
Bing-Cheng Hu ◽  
Xue-Hai Ju
Keyword(s):  
Energetic Materials ◽  
Density Functional ◽  
Hot Spot ◽  
High Energy ◽  
High Energy Density ◽  
Heats Of Formation ◽  
Detonation Properties ◽  
Energetic Compounds ◽  
High Nitrogen ◽  
Functional Theory

Abstract High nitrogen energetic compounds have always been a hot spot in energetic materials. In this work, we provide a new approach for the design of promising energetic molecules containing pentazole. Attractive energetic compounds include 5-amino-3-nitro-1H-1,2,4-triazole (ANTA) and 5-nitro-1,2,4-triazol-3-one(NTO) are used to effectively combine with pentazole to form a series of pentazole derivatives. Then, the NH2, NO2 or NF2 groups were introduced into the system to further adjust the property. Herein, the structures and densities of designed compounds as well as the heats of formation, detonation properties and impact sensitivities were predicted based on density functional theory (DFT). The results show that all ten designed molecules have excellent densities (1.81 g/cm3 to 1.97 g/cm3) and high heats of formation (621.66 kJ/mol to 1374.63 kJ/mol). Furthermore, detonation performances of compounds A3 (P = 41.16 GPa and D = 9.45 km/s) and A4 (P = 43.90 GPa and D = 9.69 km/s) are superior to 1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), and lower impact sensitivity than HMX. It exhibited that they could be taken as promising candidates of high-energy density materials. This work provides a worthy way to explore the energetic compounds with excellent performance based on pentazole.

A Rare Low Spin Co(IV) Bis-Silyldiamide with High Thermal Stability: Exploring the Origin of an Unusual S = 1/2 Configuration

2020 ◽  
Author(s):  
David Zanders ◽  
Goran Bačić ◽  
Dominique Leckie ◽  
Oluwadamilola Odegbesan ◽  
Jeremy M. Rawson ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
Atomic Layer ◽  
Epr Spectrum ◽  
Functional Theory ◽  
Cluster Calculations ◽  
Layer Deposition ◽  
Starting Point ◽  
Higher Spin ◽  
Surface Saturation

Attempted preparation of a chelated Co(II) β-silylamide re-sulted in the unprecedented disproportionation to Co(0) and a spirocyclic cobalt(IV) bis(β-silyldiamide): [Co[(NtBu)2SiMe2]2] (1). Compound 1 exhibits a room temperature magnetic moment of 1.8 B.M and a solid state axial EPR spectrum diagnostic of a rare S = 1/2 configuration. Semicanonical coupled-cluster calculations (DLPNO-CCSD(T)) revealed the doublet state was clearly preferred (–27 kcal/mol) over higher spin configurations for which density functional theory (DFT) showed no energetic preference. Unlike other Co(IV) complexes, 1 had remarkable thermal stability, and was demonstrated to form a stable self-limiting monolayer in initial atomic layer deposition (ALD) surface saturation tests. The ease of synthesis and high-stability make 1 an attractive starting point to begin investigating otherwise inaccessible Co(IV) intermediates and synthesizing new materials.

scholarly journals Computational Study of the Electron Spectra of Vapor-Phase Indole and Four Azaindoles

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1947
Author(s):  
Delano P. Chong
Keyword(s):  
Density Functional Theory ◽  
Vapor Phase ◽  
Density Functional ◽  
Computational Study ◽  
Geometry Optimization ◽  
The Other ◽  
Functional Theory ◽  
Electron Spectra

After geometry optimization, the electron spectra of indole and four azaindoles are calculated by density functional theory. Available experimental photoemission and excitation data for indole and 7-azaindole are used to compare with the theoretical values. The results for the other azaindoles are presented as predictions to help the interpretation of experimental spectra when they become available.

scholarly journals Thermal Stability and Decomposition Kinetics of 1-Alkyl-2,3-Dimethylimidazolium Nitrate Ionic Liquids: TGA and DFT Study

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2560
Author(s):  
Jianwen Meng ◽  
Yong Pan ◽  
Fan Yang ◽  
Yanjun Wang ◽  
Zhongyu Zheng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Density Functional Theory ◽  
Ionic Liquids ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Nitrogen Atmosphere ◽  
Decomposition Kinetics ◽  
Heating Rates ◽  
Functional Theory ◽  
Kinetics Of

The thermal stability and decomposition kinetics analysis of 1-alkyl-2,3-dimethylimidazole nitrate ionic liquids with different alkyl chains (ethyl, butyl, hexyl, octyl and decyl) were investigated by using isothermal and nonisothermal thermogravimetric analysis combined with thermoanalytical kinetics calculations (Kissinger, Friedman and Flynn-Wall-Ozawa) and density functional theory (DFT) calculations. Isothermal experiments were performed in a nitrogen atmosphere at 240, 250, 260 and 270 °C. In addition, the nonisothermal experiments were carried out in nitrogen and air atmospheres from 30 to 600 °C with heating rates of 5, 10, 15, 20 and 25 °C/min. The results of two heating modes, three activation energy calculations and density functional theory calculations consistently showed that the thermal stability of 1-alkyl-2,3-dimethylimidazolium nitrate ionic liquids decreases with the increasing length of the alkyl chain of the substituent on the cation, and then the thermal hazard increases. This study could provide some guidance for the safety design and use of imidazolium nitrate ionic liquids for engineering.

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