3-硝基-1,2,4-三唑-5-酮与NH3及H2O分子间相互作用的理论研究

在DFT—B3LYP／6—311 G^**水平上,求得3-硝基-1,2,4-三唑-5-酮(NTO)／NH3和NTO／H2O两种超分子体系势能面上5种全优化构型．经基组叠加误差(BSSE)和零点能(ZPE)校正,求得NTO与NH3和H2O的分子间最大相互作用能依次为-37．58和-30．14kJ／mol,表明NTO与NH3的分子问相互作用强于与H2O的作用．超分子体系中电子均由NH3或H2O向NTO转移,相互作用能主要由强氢键所贡献,由自然键轨道分析揭示了相瓦作用的本质．对优化构型进行振动分析,并基于统计热力学求得200．0～800．0K温度范围从单体形成超分子的热力学性质变化．发现由NTO和NH3形成超分子Ⅱ和Ⅲ在常温下可自发进行;而NTO和H2O只在低温下才能自发形成Ⅳ,Ⅴ和Ⅵ超分子．     

1H-ANTA二聚体分子间相互作用的密度泛函理论研究

在DFT-B3LYP/6-311＋＋G**水平上求得1H-3-硝基-5-氨基-1,2,4-三唑(1H-ANTA)二聚体势能面上5种优化构型和电子结构. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得分子间最大结合能为70.63 kJ/mol. 二聚体的形成使电荷向三唑环转移. 由氢键强弱推断二聚体稳定性的顺序与结合能顺序相一致, 氢键是二聚体的主要作用形式. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围内单体形成二聚体的热力学性质变化. 发现在该温度范围所有二聚过程均能自发进行.     

3-硝基-1,2,4-三唑-5-酮与NH3及H2O分子间相互作用的理论研究

在DFT-B3LYP/6-311＋＋G**水平上, 求得3-硝基-1,2,4-三唑-5-酮(NTO)/NH₃和NTO/H₂O两种超分子体系势能面上5种全优化构型. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得NTO与NH₃和H₂O的分子间最大相互作用能依次为－37.58和－30.14 kJ/mol, 表明NTO与NH₃的分子间相互作用强于与H₂O的作用. 超分子体系中电子均由NH₃或H₂O向NTO转移, 相互作用能主要由强氢键所贡献, 由自然键轨道分析揭示了相互作用的本质. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围从单体形成超分子的热力学性质变化. 发现由NTO和NH₃形成超分子II和III在常温下可自发进行; 而NTO和H₂O只在低温下才能自发形成IV, V和VI超分子.     

Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Nitroamine Dimers

Ab initio self-consistent field(SCF) and Mφller-Plesset correlation correction methods employing 6-31G^** basis set have been applied to the optimizations of nitroamine dimers.The binding energies have been corrected for the basis set superposition error (BSSE) and the zero-point energy.Theree optimized dimers have been obtained.The BSSE corrected binding energy of the most stable dimer is predicted to be -31.85kJ/mol at the MP4/6-31G^**//MP2/6-31G^** level.The energy barriers of the Walden conversion for -NH2 group are 19.7kJ/mol and 18.3kJ/mol for monomer and the most stable dimer,respectively.The molecular interaction makes the internal rotation around N1-N2 even more difficult.The thermodynamic properties of nitroamine and its dimers at different temperatures have been calculated on the basis of vibrational analyses.The change of the Gibbs free energy for the aggregation from monomer to the most stable dimer at standard pressure and 298.2 K is predicted to be 14.05kJ/mol.     

NTO二聚体分子间相互作用的理论研究

在DFT-B3LYP/6-311＋＋G**水平上求得NTO二聚体势能面上六种优化构型和电子结构. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得分子间最大相互作用能为－53.66 kJ/mol. 二子体系间的电荷转移很少. 由自然键轨道分析揭示了相互作用的本质. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围从单体形成二聚体的热力学性质变化. 发现二聚主要由强氢键所贡献, 但结合能大小并不为氢键所完全决定. 二聚过程在较低温度或常温下能自发进行.     

新型高能炸药热分解研究进展

炸药的热分解对其安定性和库存可靠性等研究是很重要的。本文总结了国内外有关TNAZ(1,3,3-三硝基氮杂环丁烷)、NTO(3-硝基-1,2,4-三唑-5-酮)、LLM-105(1-氧-2,6-二氨基-3,5-二硝基吡嗪)、FOX-7(1,1-二氨基-2,2-二硝基乙烯)等几种新型高能炸药的热分解研究。分别从理论上、实验上阐述了它们的热分解研究现状,指出了以前研究中存在的问题,预测了钝感高能炸药热分解的发展前景。参考文献32篇。     

Density functional theory investigation on the degradation mechanisms of 3-nitro-1,2,4-triazol-5-one (NTO) in water

Structural Chemistry - The degradation mechanisms of 3-nitro-1,2,4-triazol-5-one (NTO) in the bulk water were explored at the density functional theory (DFT) level using the M06-2X functional and...     

Effect of pressure on the vibrational structure of insensitive energetic material 5-nitro-2,4-dihydro-1,2,4-triazole-3-one

The Raman spectra of alpha form 5-nitro-2,4-dihydro-1,2,4-triazole-3-one (alpha-NTO, space group P) were measured in a high-pressure vessel diamond anvil cell (DAC). The pressure was increased to 27.6 GPa. In general, Raman bands show a blue shift because of the nature of the molecule packing as a high-pressure effect, but some particular bands exhibited a red shift, disappearance, split, or slight shifting in our experiments. Those red-shifting bands concerning hydrogen bonds, i.e., carbonyl and amino groups, are likely to work as a stabilizer against stimuli to the molecule or crystal. This stabilizing nature might characterize the insensitivity of NTO. Molecular dynamic (MD) calculations were performed to reveal the high-pressure effect of the alpha-NTO crystal. The coordinates of individual atoms in the crystal structure were obtained using X-ray diffraction analysis. The pressure dependence of the power spectra of the correlation functions of the C=O bond length in NTO was calculated. A unique high-pressure effect of the alpha-NTO crystal was found on the power spectra. The peak frequency in the power spectrum of the C=O stretching vibration exhibited a red shift with an increase in pressure to 10.0 GPa, while the peak intensity considerably decreased under the same pressure process, because this bond length increased with an increase in pressure to 10.0 GPa. At a pressure of >20.0 GPa, a blue shift appeared. These results of the MD calculations are in good agreement with our experimental data.     

Density functional theory study of the interaction between 3‐nitro‐1,2,4‐triazole‐5‐one and ammonia

Two fully optimized geometries of 3‐nitro‐1,2,4‐triazol‐5‐one (NTO)–NH₃ complexes have been obtained with the density function theory (DFT) method at the B3LYP/6‐311++G** level. The intermolecular interaction energy is calculated with zero point energy (ZPE) correction and basis set superposition error (BSSE) correction. The greatest corrected intermolecular interaction of the NTO–NH₃ complexes is ?37.58 kJ/mol. Electrons in complex systems transfer from NH₃ to NTO. The strong hydrogen bonds contribute to the interaction energies dominantly. Natural bond orbital (NBO) analysis is performed to reveal the origin of the interaction. Based on vibrational analysis, the changes of thermodynamic properties from the monomer to complexes with the temperature ranging from 200 K to 800 K have been obtained using the statistical thermodynamic method. It is found that two NTO–NH₃ complexes can be produced spontaneously from NTO and NH₃ at normal temperature. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005     

Theoretical Study on the Intermolecular Interactions of Tetrazole Dimers

1 INTRODUCTION Tetrazole and its derivatives are widely applied in the fields of agriculture, biology, chemistry, phar- macology and photographic technology, and they play significant roles in the science and technology as well as national defence[1]. In the past, the res- earches were focused on the molecular geometries, electronic structures, IR, thermodynamic properties, tautomerization, pyrogenation and sensitivity of tetrazole compounds[1～5]. However, study of tetra- zole dimers ha…     

α-Oxides in reaction with N-H acids of the heterocyclic series

Anumber of 1-methyl-4-(2-hydroxyalkyl)-3-nitro-1,2,4-triazol-5-ones and their derivatives were obtained by reaction of 1-methyl-3-nitro1,2,4-triazol-5-one with -epoxides. The fact of intramolecular nucleophilic substitution of the nitro group in hydroxy derivatives of 3-nitro-1,2,4-triazol-5-one with cyclization to 2-methyl-3-oxo-5,6-dihydrooxazolo[3,2-b]-1,2,4-triazoline was established.See [1] for communication III.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1407–1410, October, 1977.     

NTO纯度标准物质定值研究

为了对纯度标准物质3-硝基-1,2,4-三唑-5-酮(NTO)定值,获得其纯度值和不确定度,采用"杂质扣除法"对标准物质进行定值,用化学分析法对定值结果进行验证.通过对定值过程的A、B类不确定度评定,获得定值结果的不确定度.NTO纯度标准物质的纯度值为99.57%,扩展不确定度U=0.02%(k=2).     

Theoretical Study on the Intermolecular Interactions between 1,1‐Diamino‐2,2‐Dinitroethylene and H2O

The density functional method was applied to the study of 1,1‐diamino‐2,2‐dinitroethylene (Fox‐7)/H₂O dimer. All the possible dimers ( 1, 2 and 3 ), as well as the monomers, were fully optimized with the DFT method at the B3LYP/6‐311++G^** level. The basis set superposition errors (BSSE) are 4.62, 4.07 and 3.45 kJ/mol, and the zero point energy (ZPE) corrections for the interaction energies are 7.94, 5.66 and 6.40 kJ/mol for 1, 2 and 3 , respectively. Dimer 1 is the most stable, judged by binding energy. After BSSE and ZPE corrections, the greatest corrected intermolecular interaction energy of dimer 1 was predicted to be ?29.36 kJ/mol. The charge redistribution mainly occurs on the adjacent N–H··· O atoms and N–O··· H atoms between submolecules. The oxygen in the nitro group acts as a moderate hydrogen acceptor as compared to water oxygen. Based on the statistical thermodynamic method, the standard thermodynamic functions, heat capacities (C⁰_P), entropies (S⁰_T) and thermal corrections to enthalpy (H⁰_T), and the changes of thermodynamic properties on going from monomer to dimer over the temperature range 200.00‐700.00 K were predicted. It is energetically or thermodynamically favorable for Fox‐7 to bind with H₂O and to form dimer 1 at room temperature.     

Theoretical Studies on Intermolecular Interactions of 4-Amino-5-nitro-1,2,3-triazole Dimers

1 INTRODUCTION Triazole, a five-membered heterocyclic compound with three nitrogen atoms, is an important interme- diate product of medicine and chemical industry as well as insecticide [1]. Due to its small volume and high nitrogenous density, triazole holds more and more attraction for the material researchers, espe- cially the researchers of high-energy insensitive explosive. It is reported that its nitro and amino deri- vatives are a sort of important high-energy mate- rials[2]. Previ…     

Synthesis of nucleosides of 5-substituted-1,2,4-triazole-3-carboxamides

Nucleosides of 5-substituted-1,2,4-triazole-3-carboxamides were prepared by the acid-catalyzed fusion procedure and by glycosylation of the appropriate trimethylsilyl derivative. The following nucleosides were obtained in two steps starting from methyl 4-substituted-1,2,4-triazole-3-carboxylates: 5-chloro-1-β- D -ribofuranosyl-1,2,4-triazole-3-carboxamide ( 6 ), 3-chloro-1-β- D -ribofuranosyl-1,2,4-triazole-5-carboxamide ( 5 ), 3-nitro-1-β- D -ribofuranosyl-1,2,4-triazole-5-carboxamide ( 12 ), 3-amino-1-β- D -ribofuranosyl-1,2,4-triazole-5-carboxamide ( 13 ), 5-methyl-1-β- D -ribofuranosyl-1,2,4-triazole-3-carboxamide ( 15 ), and 3-methyl-1-β- D -ribofuranosyl-1,2,4-triazole-5-carboxamide ( 16 ). In addition, 5-amino-1-β- D -ribofuranosyl-1,2,4-triazole-3-carboxamide ( 7 ), and 1-β- D -ribofuranosyl-1,2,4-triazole-3-carboxamide-5-thiol ( 8 ) were prepared from 6 .     

Examination of formamide,formamidic acid,amidine dimers,and the double proton transfer transition states involving these dimers

Structures and relative energies were obtained for the hydrogen bonded dimers of formamide and formamidic acid using the 3-21G basis set. A double proton transfer transition state is claimed to link these two dimers. While the structure of the transition state was intermediate between those of the two dimers, the energy was only 7.6 kJ/mol greater than the less stable formamidic acid dimer. The activation energy from the formamide dimer side of the reaction was found to be 125 kJ/mol of dimer. A similar transition state was found for the amidine dimer system. The activation energy for this model reaction was found to be 66.9 kJ/mol of dimer.     

Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Dimethylnitroamine Clusters

Ab initio SCF and Mφller-Plesset correlation correction methods in combination with counterpose procedure for BSSE correction have been applied to the theroetical studying of dimethylnitroamine and its dimers and trimers.Three optimized stable dimers and two trimers have been obtained.The corrected binding energies of the most stable dimer and trimer were predicted to be -24.68kJ/mol and -47.27kJ/mol,respectively at the MP2/6-31G^*//HF/6-31G^* level.The proportion of correlated interation energies to their total interaction energies for all clusters was at least 29.3 percent,and the BSSE of ΔE(MP2) was at least 10.0kJ/mol.Dispersion and/or electrostatic force were dominant in all clusters.There exist cooperative effects in both the chain and the cyclic trimers.The vibrational frequencies associated with N-O stretches or wags exhibit slight red shifts,but the modes associated with the motion of hydrogen atoms of the methyl group show somewhat blue shifts with respect to those of monomer.Thermodynamic properties of dimethylnitroamine and its clusters at different temperatures have been calculated on the basis of vibrational analyses.The changes of the Gibbs free energies for the aggregation from monomer to the most stable dimer and trimer were predicted to be 14.37kJ/mol and 30.40kJ/mol,respectively,at 1 atm and 298.15K.     

Ab initio Studies on Intermolecular Interaction of Formamide and Hydroxyacetonitrile Dimers

The structures, the binding energies and the thermodynamic properties of formamide and hydroxyacetonitrile(HAN) dimers have been studied by means of the self-consistent ab initio Hartree-Fock and the second-order Mφller-Plesset correlation energy correction methods. The counterpoise procedure was used to check the basis set superposition error(BSSE) of the binding energies. There exist cyclic structures in a formamide dimer(Ⅰ), a HAN dimer(Ⅱ) and their heterodimer(Ⅲ). The corrected binding energies for dimers Ⅰ, Ⅱ and Ⅲ are respectively -45.53, -45.83 and -43.89 kJ/mol at the MP2/aug-cc-p VDZ//HF/aug-cc-p VDZ level. The change of the Gibbs free energies(ΔG) in the process of Ⅰ Ⅱ→2Ⅲ was predicted to be -2.74 kJ/mol at 298.15 K. Dimer Ⅲ can be spontaneously produced in the mixture of formamide and HAN, which is in agreement with the experimental fact that most cyanohydrins are capable of interacting with dipeptide cyclo-His-Phe(CHP).     

Na(NTO)(H2O)的制备、晶体结构及热力学性质研究

利用氢氧化钠溶液与NTO水溶液进行反应制备了标题化合物并培养出单晶。通过X射线单晶结构分析法测定分子结构和晶体结构,其分子式可表示为Na(NTO)(H2O),晶体属单斜晶系,P21/c空间群,晶体学参数为:a=0.6303(1)nm,b=0.8285(1)nm,c=1.1574(2)nm,β=103.85(1)°,V=0.5868(2)nm^3,Dc=1.925g/cm^3,Z=4,F(000)=344,μ=0.238mm^-1,R=0.0259。通过Na(NTO)(H2O)在水中溶解焓的测定,算得其标准生成焓、晶格焓和晶格能。     

Intermolecular interactions,thermodynamic properties,crystal structure,and detonation performance of HMX/NTO cocrystal explosive

Previous studies have shown that the design of cocrystal explosives is one of the most promising approaches to decrease the sensitivity and maintain the detonation performance of existing explosives. As is well‐known, octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) is a high energy density material (HEDM). But the application of HMX is limited, due to its high sensitivity. Thus, an insensitive explosive 5‐nitro‐1,2,4‐triazol‐3‐one (NTO) is proposed as a cocrystal former (CCF) to cocrystallize with HMX in the present work. The binding energies, heat of formations (HOFs), thermodynamic properties, atoms in molecules, and natural bond orbital analysis of four HMX/NTO complexes have been calculated using density functional theory methods, including meta‐hybrid functional (M062X) and dispersion‐corrected density functionals (B97D, ωB97XD). In addition, the crystal structure of HMX/NTO cocrystal has been investigated using Monte Carlo simulation and first principles methods. The HMX/NTO cocrystal is most likely to crystallize in triclinic crystal system with P1 space group, and corresponding cell parameters are Z = 2, a = 9.06 Å, b = 8.19 Å, c = 10.27 Å, α = 81.94^°, β = 98.42^°, γ = 82.03^°, and ρ = 1.92 g/cm³. The detonation velocity and detonation pressure of HMX/NTO cocrystal are 8.73 km/s and 35.14 GPa, respectively, a little lower than those of HMX. Finally, bond dissociation energies (BDEs) of the weakest trigger bond in HMX/NTO complexes are calculated. The results show that HMX/NTO complexes are thermally stable and meet the thermal requirement of HEDMs (BDE > 120 kJ/mol). © 2012 Wiley Periodicals, Inc.