Design of new aliphatic azido nitro compounds as plasticizer: an initial exploration on AFCTEE (1-azido-formic acid 1,1,1-trinitro-ethyl ester)

2015 ◽  
Vol 93 (7) ◽  
pp. 690-695 ◽  
Author(s):  
Junqing Yang ◽  
Xuedong Gong ◽  
Guixiang Wang
Keyword(s):  
Thermal Stability ◽  
Formic Acid ◽  
Ethyl Ester ◽  
Chemical Stability ◽  
Density Functional ◽  
High Energy ◽  
Nitro Compounds ◽  
Functional Theory ◽  
Energetic Properties ◽  
Initial Exploration

To explore new high-energy azido nitro compounds as plasticizers for propellants, AFCTEE (1-azido-formic acid 1,1,1-trinitro-ethyl ester) was designed and studied using density functional theory. The predicted density of AFCTEE, 1.90 gcm−3, is comparable to that of HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane) and much higher than that of general organic azido compounds. AFCTEE possesses higher energetic properties and chemical stability than the promising azido nitro plasticizer DAMNP (1,3-diazido-2-methyl-2-nitropropane) and the conventional plasticizer NG (nitroglycerine), and it has a moderate thermal stability. The pyrolysis of AFCTEE starts from the rupture of C–NO2 and then the breakage of N–N2 via Curtius rearrangement. This work is the initial exploration for AFCTEE, aiming at the energetics, spectra (IR, NMR, and UV), stability, and decomposition mechanism. Compared with DAMNP, the advantages of superior energetic properties and chemical stability suggest AFCTEE is a promising energetic azido nitro compound and is worth further investigation.

Comparing the performance of aliphatic azido nitramines, nitrate esters, and nitro compounds: theoretical design and investigation

2015 ◽  
Vol 93 (11) ◽  
pp. 1232-1238
Author(s):  
Junqing Yang ◽  
Guixiang Wang ◽  
Xuedong Gong ◽  
Xiaoan Wei
Keyword(s):  
Thermal Stability ◽  
Thermodynamic Properties ◽  
Density Functional ◽  
Density Functional Theory Method ◽  
Nitro Compounds ◽  
Oxygen Balance ◽  
Nitrate Esters ◽  
Energetic Properties ◽  
The Density Functional Theory ◽  
Theoretical Investigations

To improve the low density and oxygen balance of the pure azido compounds, experimental research has been devoted to developing the modified azido compounds, such as azido nitramines, azido nitrate esters, and azido nitro compounds. Using the experimental methods to obtain a compound with suitable performance needs more resources than using theoretical tests, which makes the theoretical investigations meaningful. In this work, three azido compounds (I, II, and III) and their 27 modified derivatives were designed and studied using the density functional theory method. Results show that –NNO2, –NO2, and –ONO2 all can improve the thermodynamic and energetic properties and the increment increases with the increasing number of substituent groups. The contribution to the thermodynamic properties is –ONO2 > –NO2 > –NNO2 and that to the energetic properties is –NNO2 > –ONO2 > –NO2. The azido nitramines possess the best energetic properties and azido nitrate esters have the best thermodynamic properties. These substituents slightly decrease the thermal stability and the azido nitrate esters possess the lowest thermal stability. Systematical inspection of the substituent effect can direct experimental researchers to synthesize modified azido compounds purposefully and selectively.

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.

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 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.

First principle simulation on oxidation mechanism of diethyl ether by nitrogen dioxide

2015 ◽  
Vol 14 (03) ◽  
pp. 1550020 ◽  
Author(s):  
Yuan Yuan ◽  
Wei Hu ◽  
Xuhui Chi ◽  
Cuihua Li ◽  
Dayong Gui ◽  
...  
Keyword(s):  
Diethyl Ether ◽  
Energy Barrier ◽  
Density Functional ◽  
Oxidation Process ◽  
Oxidation Mechanism ◽  
High Energy ◽  
First Principle ◽  
Functional Theory ◽  
The Third ◽  
High Energy Barrier

The oxidation mechanism of diethyl ethers by NO2was carried out using density functional theory (DFT) at the B3LYP/6-31+G (d, p) level. The oxidation process of ether follows four steps. First, the diethyl ether reacts with NO2to produce HNO2and diethyl ether radical with an energy barrier of 20.62 kcal ⋅ mol-1. Then, the diethyl ether radical formed in the first step directly combines with NO2to form CH3CH ( ONO ) OCH2CH3. In the third step, the CH3CH ( ONO ) OCH2CH3was further decomposed into the CH3CH2ONO and CH3CHO with a moderately high energy barrier of 32.87 kcal ⋅ mol-1. Finally, the CH3CH2ONO continues to react with NO2to yield CH3CHO , HNO2and NO with an energy barrier of 28.13 kcal ⋅ mol-1. The calculated oxidation mechanism agrees well with Nishiguchi and Okamoto's experiment and proposal.

DFT study on thermo-elastic properties of Ru2FeZ (Z = Si, Ge, Sn) Heusler alloys

2018 ◽  
Vol 32 (05) ◽  
pp. 1850045 ◽  
Author(s):  
Aneeza Iftikhar ◽  
Afaq Ahmad ◽  
Iftikhar Ahmad ◽  
Muhammad Rizwan
Keyword(s):  
Thermal Stability ◽  
Elastic Properties ◽  
Density Functional ◽  
Heusler Alloys ◽  
Longitudinal Mode ◽  
Transverse Mode ◽  
Functional Theory ◽  
Formation Energies ◽  
Thermal Stability Of ◽  
Temperature Melting

We studied the thermo-elastic properties of Ru2FeZ (Z[Formula: see text]=[Formula: see text]Si, Ge, Sn) Heusler alloys within the framework of density functional theory. Thermo-elastic properties corresponding to elastic modulus, anisotropy, phase stability, elastic wave velocities, thermal stability, Debye temperature, melting temperature, thermal conductivity and formation energy are calculated. The elastic constants C[Formula: see text] predict the structural and dynamical stabilities while the formation energies show thermal stability of the alloys at 0 K. Pugh’s and Poisson’s ratios display the ductile nature of alloys. All alloys are anisotropic and we also observed that Ru2FeSn is the hardest material than Ru2FeSi and Ru2FeGe. Moreover, longitudinal mode of vibrations are also observed and are maximum along [100], [110] and [111] directions than the transverse mode of vibrations.

Molecular design on a new family of azaoxaadamantane cage compounds as potential high-energy density compounds

2019 ◽  
Vol 97 (2) ◽  
pp. 86-93 ◽  
Author(s):  
Yong Pan ◽  
Weihua Zhu ◽  
Heming Xiao
Keyword(s):  
Thermal Stability ◽  
Density Functional ◽  
Parent Compound ◽  
High Energy ◽  
High Energy Density ◽  
Lower Sensitivity ◽  
Detonation Properties ◽  
Detonation Pressure ◽  
Cage Compounds ◽  
New Family

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.

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