The effect of aluminum on FOX-7 structure was considered. Density functional approach at the level of unrestricted B3LYP/6-311++G(d,p) level was adopted. The model considered 1-4 aluminum atoms per FOX-7 molecule. The...The effect of aluminum on FOX-7 structure was considered. Density functional approach at the level of unrestricted B3LYP/6-311++G(d,p) level was adopted. The model considered 1-4 aluminum atoms per FOX-7 molecule. The results show that the molecular geometries as well as many molecular orbital characteristics of FOX-7 molecule are subjected multiplicity of the composites, FOX-7 + n Al ( n =1-4). In the case of n =1-2, some conformational changes occur. In the presence of three aluminum atoms, the quartet state of the composite is stable but in the doublet state, one of the N—O bonds ruptures. As for the n =4 case the singlet and triplet states are stable but in the quintet state one of the N—O bonds cleaves. As the number of aluminum atoms increases, the HOMO-LUMO energy gap decreases generally.展开更多
A new energetic material,4,5-dimethoxy-2-（dinitromethylene）imidazolidine（DMDNI）,was synthesized by the reaction of 4,5-dihydroxyl-2-（dinitromethylene）-imidazolidine（DDNI） and methanol,and structurally characte...A new energetic material,4,5-dimethoxy-2-（dinitromethylene）imidazolidine（DMDNI）,was synthesized by the reaction of 4,5-dihydroxyl-2-（dinitromethylene）-imidazolidine（DDNI） and methanol,and structurally characterized by single crystal X-ray diffraction.DMDNI crystallized in triclinic space group P1,with crystal data a=0.4324（4） nm,b=1.3599（11） nm,c=1.7503（14） nm,α=77.406（14）°,β=84.494（15）°,γ=87.976（14）°,V=0.9997（14） nm 3,Z=4,μ=0.140 mm-1,F（000）=488,D c =1.556 g/cm ^3,R 1 =0.0773 and wR 2 =0.1574.Thermal decomposition of DMDNI was studied,and its thermal decomposition process was divided into two stages.The first stage was a melting process and the second stage was an exothermic decomposition process.The enthalpy,apparent activation energy and pre-exponential constant of the exothermic decomposition reaction are-491.5 J/g,142.3 kJ/mol and 10 14.24 s^-1,respectively.The critical temperature of thermal explosion is 162.47 °C.DMDNI has a lower thermal stability than DDNI but it is close to that of 4,5-diacetoxyl-2-（dinitromethylene）-imidazolidine（DADNI）.展开更多
The adsorption of 1,1-diamino-2,2-dinitroethylene （FOX-7） molecule on the AI（I 11） surface was investigated by the generalized gradient approximation （GGA） of density functional theory （DFT）. The calculations ...The adsorption of 1,1-diamino-2,2-dinitroethylene （FOX-7） molecule on the AI（I 11） surface was investigated by the generalized gradient approximation （GGA） of density functional theory （DFT）. The calculations employ a supercell （4 × 4 × 2） slab model and three-dimensional periodic boundary conditions. The strong attractive forces between oxygen and aluminum atoms induce the N--O bond breaking of the FOX-7. Subsequently, the dissociated oxygen atoms and radical fragment of FOX-7 oxidize the AI surface. The largest adsorption energy is --940.5 kJ/mol. Most of charge transfer is 3.3 le from the A1 surface to the fragment of FOX-7 molecule. We also investi- gated the adsorption and decomposition mechanism of FOX-7 molecule on the AI（111） surface. The activation en- ergy for the dissociation steps of P2 configuration is as large as 428.8 kJ/mol, while activation energies of other configurations are much smaller, in range of 2.4 to 147.7 kJ/mol.展开更多
The thermal behavior and non-isothermal decomposition kinetics of [Cu（en）2H2O]（FOX-7）2·H2O （en=ethylenediamine） were studied with DSC and TG-DTG methods.The kinetic equation of the exothermal process is dα...The thermal behavior and non-isothermal decomposition kinetics of [Cu（en）2H2O]（FOX-7）2·H2O （en=ethylenediamine） were studied with DSC and TG-DTG methods.The kinetic equation of the exothermal process is dα/dt=（10^17.92/β）4α^3/4exp（-1.688×10^5/RT）.The self-accelerating decomposition temperature and critical temperature of the thermal explosion are 163.3 and 174.8 ℃,respectively.The specific heat capacity of [Cu（en）2H2O]（FOX-7）2·H2O was determined with a micro-DSC method,with a molar heat capacity of 661.6 J·mol^-1·K^-1 at 25 ℃.Adiabatic time-to-explosion was also estimated as 23.2 s.[Cu（en）2H2O]（FOX-7）2·H2O is less sensitive.展开更多
以1,1'-二氨基-2,2'-二硝基乙烯(FOX-7)为原料,经浓硝酸硝化及有机溶剂萃取得到高氧平衡化合物——四硝基乙酰胺酸(TNAA)。对比了四种有机萃取溶剂(二氯甲烷、氯仿、四氯化碳和乙酸乙酯)所得TNAA的收率及纯度。采用DSC和TG研究...以1,1'-二氨基-2,2'-二硝基乙烯(FOX-7)为原料,经浓硝酸硝化及有机溶剂萃取得到高氧平衡化合物——四硝基乙酰胺酸(TNAA)。对比了四种有机萃取溶剂(二氯甲烷、氯仿、四氯化碳和乙酸乙酯)所得TNAA的收率及纯度。采用DSC和TG研究了TNAA的热行为。结果表明,确定二氯甲烷为最佳萃取溶剂,其收率为95.0%,纯度为99.4%。升温速率10 K·min^(-1)下,TNAA熔化吸热峰的初始温度、峰值温度分别为84.8℃和87.8℃,熔融焓为61.7 J·g^(-1);分解放热峰的初始温度、峰值温度分别为117.7℃和131.4℃,分解热为934.8 J·g^(-1)。采用Kissinger方法得到的TNAA的热分解反应活化能E为124.7 k J·mol^(-1),指前因子A为10^(16.1)s^(-1)。自加速分解温度T_(SADT)为102.3℃、热爆炸临界温度T_b为112.2℃、T=Tp时TNAA热分解反应的热力学参数ΔH~≠、ΔS~≠以及ΔG~≠,分别为121.5 k J·mol^(-1)、61.2 J·K^(-1)·mol^(-1)和98.0 k J·mol^(-1)。展开更多
文摘The effect of aluminum on FOX-7 structure was considered. Density functional approach at the level of unrestricted B3LYP/6-311++G(d,p) level was adopted. The model considered 1-4 aluminum atoms per FOX-7 molecule. The results show that the molecular geometries as well as many molecular orbital characteristics of FOX-7 molecule are subjected multiplicity of the composites, FOX-7 + n Al ( n =1-4). In the case of n =1-2, some conformational changes occur. In the presence of three aluminum atoms, the quartet state of the composite is stable but in the doublet state, one of the N—O bonds ruptures. As for the n =4 case the singlet and triplet states are stable but in the quintet state one of the N—O bonds cleaves. As the number of aluminum atoms increases, the HOMO-LUMO energy gap decreases generally.
基金Supported by the National Natural Science Foundation of China(No.20803058)the Basal Science Foundation of National Defense(No.B0920110005)+1 种基金the Science Program Foundation of Shaanxi Province,China(No.2011kjxx31)the Education Committee Foundation of Shaanxi Province,China(No.2010JK881)
文摘A new energetic material,4,5-dimethoxy-2-（dinitromethylene）imidazolidine（DMDNI）,was synthesized by the reaction of 4,5-dihydroxyl-2-（dinitromethylene）-imidazolidine（DDNI） and methanol,and structurally characterized by single crystal X-ray diffraction.DMDNI crystallized in triclinic space group P1,with crystal data a=0.4324（4） nm,b=1.3599（11） nm,c=1.7503（14） nm,α=77.406（14）°,β=84.494（15）°,γ=87.976（14）°,V=0.9997（14） nm 3,Z=4,μ=0.140 mm-1,F（000）=488,D c =1.556 g/cm ^3,R 1 =0.0773 and wR 2 =0.1574.Thermal decomposition of DMDNI was studied,and its thermal decomposition process was divided into two stages.The first stage was a melting process and the second stage was an exothermic decomposition process.The enthalpy,apparent activation energy and pre-exponential constant of the exothermic decomposition reaction are-491.5 J/g,142.3 kJ/mol and 10 14.24 s^-1,respectively.The critical temperature of thermal explosion is 162.47 °C.DMDNI has a lower thermal stability than DDNI but it is close to that of 4,5-diacetoxyl-2-（dinitromethylene）-imidazolidine（DADNI）.
文摘The adsorption of 1,1-diamino-2,2-dinitroethylene （FOX-7） molecule on the AI（I 11） surface was investigated by the generalized gradient approximation （GGA） of density functional theory （DFT）. The calculations employ a supercell （4 × 4 × 2） slab model and three-dimensional periodic boundary conditions. The strong attractive forces between oxygen and aluminum atoms induce the N--O bond breaking of the FOX-7. Subsequently, the dissociated oxygen atoms and radical fragment of FOX-7 oxidize the AI surface. The largest adsorption energy is --940.5 kJ/mol. Most of charge transfer is 3.3 le from the A1 surface to the fragment of FOX-7 molecule. We also investi- gated the adsorption and decomposition mechanism of FOX-7 molecule on the AI（111） surface. The activation en- ergy for the dissociation steps of P2 configuration is as large as 428.8 kJ/mol, while activation energies of other configurations are much smaller, in range of 2.4 to 147.7 kJ/mol.
基金Supported by the National Natural Science Foundation of China（Nos. 21241003, 20803058）, the Science and Technology Research and Development Program of Shaanxi Province, China（No.2013K02-25） and the Education Committee Foundation of Shaanxi Province, China（No.2013JK0697）.
文摘The thermal behavior and non-isothermal decomposition kinetics of [Cu（en）2H2O]（FOX-7）2·H2O （en=ethylenediamine） were studied with DSC and TG-DTG methods.The kinetic equation of the exothermal process is dα/dt=（10^17.92/β）4α^3/4exp（-1.688×10^5/RT）.The self-accelerating decomposition temperature and critical temperature of the thermal explosion are 163.3 and 174.8 ℃,respectively.The specific heat capacity of [Cu（en）2H2O]（FOX-7）2·H2O was determined with a micro-DSC method,with a molar heat capacity of 661.6 J·mol^-1·K^-1 at 25 ℃.Adiabatic time-to-explosion was also estimated as 23.2 s.[Cu（en）2H2O]（FOX-7）2·H2O is less sensitive.
文摘以1,1'-二氨基-2,2'-二硝基乙烯(FOX-7)为原料,经浓硝酸硝化及有机溶剂萃取得到高氧平衡化合物——四硝基乙酰胺酸(TNAA)。对比了四种有机萃取溶剂(二氯甲烷、氯仿、四氯化碳和乙酸乙酯)所得TNAA的收率及纯度。采用DSC和TG研究了TNAA的热行为。结果表明,确定二氯甲烷为最佳萃取溶剂,其收率为95.0%,纯度为99.4%。升温速率10 K·min^(-1)下,TNAA熔化吸热峰的初始温度、峰值温度分别为84.8℃和87.8℃,熔融焓为61.7 J·g^(-1);分解放热峰的初始温度、峰值温度分别为117.7℃和131.4℃,分解热为934.8 J·g^(-1)。采用Kissinger方法得到的TNAA的热分解反应活化能E为124.7 k J·mol^(-1),指前因子A为10^(16.1)s^(-1)。自加速分解温度T_(SADT)为102.3℃、热爆炸临界温度T_b为112.2℃、T=Tp时TNAA热分解反应的热力学参数ΔH~≠、ΔS~≠以及ΔG~≠,分别为121.5 k J·mol^(-1)、61.2 J·K^(-1)·mol^(-1)和98.0 k J·mol^(-1)。
