3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪银盐的热分解反应动力学及热安全性

利用两步合成法,得到标题化合物3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪(BTATz)银盐（Ag2(BTATz)·2H2O）,并用元素分析、X荧光和红外光谱分析对其进行了结构表征。 采用DSC和TG-DTG技术对化合物进行热分解行为及非等温热分解动力学研究。 结果表明,其热分解过程是由1个吸热阶段和2个放热阶段组成,主放热阶段的非等温热分解反应动力学方程为:dα/dt=1014.29×{3(1-α)[-ln(1-α)]1/4/4}exp(-2.10×104/T)。 计算得到化合物的自加速分解温度(TSADT)、热爆炸临界温度(Tb)、热点火温度(TTIT)和绝热至爆时间（tTIAD）分别为517.10 K、580.12 K、531.00 K和90.32 s ,以此来评价其热安全性。     

高能量密度材料3,3′-偶氮-1,2,4,5-四嗪衍生物的分子设计

运用密度泛函理论(DFT)方法,计算系列3,3′-偶氮-1,2,4,5-四嗪衍生物的生成热.结果显示:—N3取代基在增加3,3′-偶氮-1,2,4,5-四嗪衍生物的生成热方面起了非常重要的作用.通过分析标题化合物的最弱键离解能发现:—NH2或—N3取代基非常有利于增加衍生物的热稳定性.计算的爆速(D)和爆压(p)数值表明:—NO2或—NF2取代基有利于提高3,3′-偶氮-1,2,4,5-四嗪衍生物的爆轰性能.综合爆轰性能和热稳定性的计算结果,3种3,3′-偶氮-1,2,4,5-四嗪衍生物可以作为潜在的品优高能量密度材料(HEDM)候选物.     

均四嗪衍生物结构、生成焓及爆轰性能的理论研究

运用DFT-w B97/6-31+G**方法对23种1,2,4,5-四嗪衍生物的几何结构、自然键轨道(NBO)和生成焓(EOF)进行研究,并在此基础上运用Kamlet-Jacobs方程估算衍生物的爆轰性能,得到其爆速在6.69~9.37 km/s之间;基于统计热力学,求得部分标题化合物在200~800 K温度范围内的热力学性质,随温度T升高,热容Cp、熵Sm及焓Hm逐渐增大。根据最小键级理论,C-R(取代基)键和N-R键可能是1,2,4,5-四嗪衍生物高温裂解的热引发键。综合分析,基团-NO2、-N3和-N=N-有助于提高四嗪衍生物的生成焓和爆轰性能,3,6-二硝基-1,2,4,5-四嗪和3,6-二偶氮基-二硝基-1,2,4,5-四嗪从能量、爆轰性能上可以作为高能量密度材料候选物。     

3,6-二肼基-1,2,4,5-四嗪的热行为、比热容及绝热至爆时间

利用差示扫描量热法(DSC)、热重-微商热重法(TG-DTG)研究了3,6-二肼基-1,2,4,5-四嗪(DHT)的热行为, 其分解过程可分为两个放热的分解过程, 且热分解反应的表观活化能分别为154.8和123.4 kJ·mol-1, 指前因子分别为1016.63和109.48 s-1. DHT热爆炸的临近温度为426.10 K. 同时, 利用微量热法和理论计算方法研究了DHT的比热容, 298.15 K时的标准摩尔比热容为183.61 J·mol-1·K-1. 计算获得了DHT的绝热至爆时间为263.84-297.58 s之间的某一值.     

1,2,4,5-四嗪含氮取代基衍生物结构和性质的理论研究

在B3LYP/aug-cc-pvDZ理论水平上研究了CN,NO2,NH2,N3,N2H,NHNH2,N4H和N4H3含氮取代基取代1,2,4,5-四嗪环上的两个氢原子生成的衍乍物,预测了它们的分f构犁、分解能及含能性质.对衍生物分解能的研究结果表明.CN取代的衍生物的分解能比未取代时更高,而其余基团的取代使分解能降低.生成热的研究显示取代基化合物的生成热越大,取代1,2,4,5-四嗪中的氢原子后生成衍生物的牛成热也越大;CN,N3和N4H取代的1,2,4,5-四嗪衍生物的单位原子生成热在83.1～95.2 kJ,比文献报道的三叠氮基-均三嗪的(70.2 kJ)更高;N4H,N3,N4H3,N2H和CN取代的1,2,4,5-四嗪衍生物,生成热在904.9～1496.6 kJ·mol-1,但N4H和N4H3取代的衍生物分解能较小,稳定性较差.     

三维无溶剂含能Ag-MOF的制备、热分解动力学及爆炸性能（英文）

溶剂分子的存在会严重降低能量金属-有机框架(EMOFs)材料的爆热和稳定性,开发无溶剂的EMOFs已成为制备高能量密度材料的有效策略。本文将高能的2,3-二(5~(-1)H-四唑基)吡嗪(H2DTPZ)配体与银离子作用在水热条件下制备了一例无溶剂的EMOF [Ag_2(DTPZ)]_n(1)(含氮量:32.58%),并借助元素分析、红外光谱、X射线衍射以及热分析等技术对其组成和结构进行了表征。化合物1中,DTPZ~(2-)配体构型高度扭转并以八齿配位模式桥联Ag+离子形成三维框架结构(ρ=2.812 g·cm~(-3)),配体大的位阻效应和强的配位能力有效阻止了溶剂分子与金属配位或占据框架空腔;同时,不同配体四唑环间强的π–π堆积作用(质心-质心距离为0.34461(1) nm),使得化合物1呈现高的热稳定性(T_e=619.1 K, T_p=658.7K)。热分析研究表明化合物1分解主要发生一步快速失重并伴有剧烈的放热,呈现出潜在的含能特质。通过差示扫描量热(DSC)技术对化合物1的热分解过程进行了非等温热动力学分析(基于Kissinger和Ozawa-Doyle方法)并获得了相应热动力学参数(活化能E_a=272.1 k J·mol~(-1),E_o=268.9 k J·mol~(-1);lgA=19.67 s~(-1))。进一步基于升温速率趋于0时的分解峰温和外延起始温度,计算得到了相关热力学参数(活化焓?H≠=266.9 k J·mol~(-1),活化熵?S≠=125.4 J·mol~(-1)·K~(-1),活化自由能?G~≠=188.3 k J·mol~(-1))以及热爆炸临界温度(T_b=607.1 K)和自加速分解温度(T_(SADT)=595.8 K),结果表明该化合物具有良好的热安全性,其分解属非自发的熵驱动过程。借助精密转动弹热量计测定了化合物1的恒容燃烧能(Q_v)并计算得其标准摩尔生成焓为(2165.99±0.81) k J·mol~(-1)。爆轰和安全性能测试表明,化合物1对撞击和摩擦均不敏感,爆热值达10.15 k J·g~(-1),远高于常见硝铵类炸药奥克托金(HMX)、黑索金(RDX)和2,4,6-三硝基甲苯(TNT),是一例有前景的高能钝感含能材料。     

一种新型连四嗪含能化合物结构设计与性能预估

为了寻找综合性能优异的含能化合物,通过含能化合物分子设计方法设计一种新型连四嗪类含能化合物ONNTO,并通过理论计算与经验公式预估其物化、爆轰、热稳定性及撞击感度等性能。结果表明,其密度为1.99 g·cm~3,生成焓为1060.67 kJ·mol~(-1),爆速为9009.38 m·s~(-1),爆压为38.19 GPa,爆热为6671.78 kJ·kg~(-1),密度、生成焓、爆热均高于黑索今和奥克托今,爆速和爆压高于黑索今,与奥克托今相当;最弱键的键离解能为376.94 kJ·mol~(-1),分解活化能为358.81 kJ·mol~(-1),均高于黑索今和奥克托今,热稳定性良好;撞击感度为23.70 cm,与黑索今和奥克托今相当,综合性能可满足作为是高能炸药的性能要求,可作为单质炸药候选物。     

BTATz-Pb复合物对双基和RDX-改性双基推进剂的热行为、非等温动力学及燃烧性能的影响

制备了含3,6-双(1-氢-1,2,3,4-四唑-5-氨基)-1,2,4,5-四嗪(BTATz)铅复合物(LCBTATZ)的双基推进剂和改性双基推进剂. 采用热重-微商热重法(TG-DTG)及差示扫描量热法(DSC)研究了其热分解行为和非等温分解动力学并在此基础上评价了其热安全性. 结果表明, LCBTATz-DB复合物中在350-540 K之间只存在一个放热分解峰, LCBTATz-CMDB复合物中存在两个连续的放热分解峰在390-540 K温度范围内, 其机理方程分别为: f(α)=α^-1/2和f(α)=2(1-α)^3/2. 计算了热加速分解温度(T_SADT)、热爆炸临界温度(T_b)、热点火温度(T_TIT)和绝热至爆时间(t_Tlad),其值分别为: DB001复合物T_SADT=444.50 K, T_TITT=453.96 K, T_b=471.84 K; t_Tlad=39.36 s; CMDB100复合物, T_SADT=442.38 K, T_TITT=452.89 K,T_b=464.13 K,t_Tlad=21.3 s,并以此来评价化合物的热安全性. 考察了LCBTATz-DB以及LCBTATz-CMDB的燃烧性能, 结果表明LCBTATZ 是一种高效的双基燃烧催化剂, 在较大的压力范围内可以显著的提高燃速并且大幅度的降低压力指数. 对于双基推进剂在2-8 MPa压力范围内出现了明显的超燃速现象, 8-12 MPa出现了“麦撒”效应, 对于改性双基推进剂的压力指数降到0.18.     

3,3′-偶氮-(6-氨基-1,2,4,5-四嗪)的合成与表征

以硝酸胍和水合肼为原料,经7步反应合成了高氮含能化合物3,3′-偶氮-(6-氨基-1,2,4,5-四嗪),其结构经1H NMR,13C NMR,IR及元素分析表征。     

3,6-二苯基-1,2-二氢-1,2,4,5-四嗪-1,2-二甲酸乙酯的合成和晶体结构

氯甲酸乙酯和3,6-二苯基-1,2-二氢-1,2,4,5-四嗪反应生成的是标题化合物3,6-二苯基-1,2-二氢-1,2,4,5-四嗪-1,2-二甲酸乙酯,而不是预期的3,6-二苯基-1,4-二氢-1,2,4,5-四嗪-1,4-二甲酸乙酯,其结构通过X射线单晶结构分析得以证实.此晶体属三斜晶系,P-1空间群,晶胞参数分别为:a=0.8915(2)nm,b=1.0444(2)nm,c=1.1509(3)nm,α=103.268(3)°,β=102.844(3)°,y=100.765(3)°,Z=2,R1=0.0593和wR2=0.1691.结果表明该化合物中心六元环的2,3-二氮杂丁二烯基团不共平面,没有很好地共轭.且该化合物中心六元环呈扭式构象,N(1)和N(2)原子分别偏离环平面-0.03611(41)和0.02944(40)nm.     

3,6-Bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine–based energetic strontium(II) complexes: synthesis,crystal structure,and thermal properties

Two energetic strontium(II) complexes with nitrogen-rich 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) were synthesized. The metal complexes were characterized by IR, elemental analysis, and single-crystal X-ray diffraction. DSC and TG-DTG were used to study the thermal behavior, non-isothermal decomposition reaction kinetics, self-accelerating decomposition temperature (T _SADT), thermal ignition temperature (T _TIT), critical temperature of thermal explosion (T _b), and the adiabatic time-to-explosion (t _TIad). The data indicate competitive energetic materials.     

Synthesis and Thermodynamic Properties of M2L[M=Li,Na; L=3,6-Bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine]

Two novel energetic alkalic metal salts of 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz), Li₂(BTATz)·6H₂O(compound 1) and Na₂(BTATz)·2H₂O(compound 2), have been synthesized by the reaction of BTATz with lithium hydroxide or sodium hydroxide in dimethylsulfoxide(DMSO) solution, respectively, and their structures were characterized by means of elemental analysis and Fourier transform infrared spectrometry(FTIR). Moreover, the single-crystal structure of compound 1 was determined by single crystal X-ray diffraction. It crystallizes in the monoclinic space group P1/c. Furthermore, their thermal decomposition behaviors were investigated by means of differential scanning calorimetry(DSC) and thermogravimetry-differential thermal gravimetry(TG-DTG). The results show that the exothermic decomposition peak temperatures for compounds 1 and 2 were 642.65 and 644.46 K, respectively, and the kinetic equations of the main exothermic decomposition were also derived from non-isothermal method. Additionally, the thermal safety of the two compounds was evaluated by calculating self-accelerating decomposition temperature(T_SADT) and critical temperature of thermal explosion(T_b). The results(the T_SADT and T_b values are 605.43 and 635.69 K for compound 1; 607.38 and 638.96 K for compound 2) reveal that the two compounds exhibit better thermal safety than BTATz.     

Synthesis and Thermal Properties of Three Energetic Ion Salts of 3,6-Bis[(1H-1,2,3,4-tetrazol-5-yl)-amino]-1,2,4,5-tetrazine

Three energetic ion salts of 3,6-bis[(1H-1,2,3,4-tetrazol-5-yl)-amino]-1,2,4,5-tetrazine(BTATz), namely, methylamine salt(compound 1), ethylenediamine salt(compound 2), and diethylamine salt(compound 3), were synthesized and characterized by elemental analysis, Fourier transform infrared spectrometry, NMR spectroscopy, and ^13C NMR spectroscopy. The crystal structure of compound 1 was determined by single-crystal X-ray crystallography, and structural analysis revealed that it belonged to the monoclinic system with P21/c space group. In addition, the thermal behavior of the three compounds was studied by differential scanning calorimetry and thermogravimetry techniques. The thermal decomposition peak temperatures of the compounds were 574.89, 545.60, and 606.72 K, indicating that the three ion salts exhibited good thermal stability. Tlie kinetic mechanism equations of the main decomposition process and the entropy of activation(△S^≠), enthalpy of activation(△H^≠), and Gibbs free energy of activation(△G^≠) of the three compounds were also obtained. Moreover, the thermal safety of the compounds was evaluated by the values of the self^accelerated decomposition temperature(Tsadt)5 thermal ignition temperature(TTIT), and critical temperature of thermal explosion(7b). The results showed that all the compounds demonstrated good thermal safety, and the thermal safety of compound 3 was better than that of the others.     

Crystal Structures,Thermal Behavior Analysis and Thermal Safety of Two Energetic Salts of Hydrazinyl-1,2,4,5-tetrazine with 3,5-Dinitrosalicylic Acid

Two energetic salts, DPHT·DNS·H₂O(1) and DHT·2DNS·2H₂O(2)[DPHT=3-(3,5-dimethyl-1H-pyrazol-1-yl)-6-hydrazinyl-1,2,4,5-tetrazine; DHT=3,6-dihydrazinyl-1,2,4,5-tetrazine], were synthesized from S-tetrazine with 3,5-dinitrosalicylic acid(DNS). Compounds 1 and 2 were structurally characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction. The thermal behavior of the title compounds was studied by differential scanning calorimetry(DSC) and thermogravimetry(TG). The non-isothermal decomposition kinetics of compound 2 were investigated. The self-accelerating decomposition temperature, thermal ignition temperature, and critical temperatures of thermal explosion were obtained to evaluate the thermal safety of compound 2. The results show compounds 1 and 2 decompose at 150.8 and 179.2℃, respectively. The T_SADT and T_b of compound 2 are higher than those of DHT, which indicates compound 2 is a potential candidate for energetic materials that have good thermal stability.     

3-硝基胍-6-(3,5-二甲基吡唑)-1,2,4,5-四嗪的晶体结构及热行为

合成了3-硝基胍-6-(3,5-二甲基吡唑)-1,2,4,5-四嗪(NDT),在二甲基甲酰胺(DMF)中培养出NDT的单晶(NDT·DMF),该晶体属于三斜晶系,P-1空间群,晶胞参数为a=0.7070(4) nm,b=0.8468(6) nm,c=1.4123(9) nm,α=73.281(8)°,β=80.423(11)°,γ=81.740(9)°,Z=2。 利用DSC和TG-DTG研究了NDT的热分解行为,其放热过程的表观活化能和指前因子分别为288.245 kJ/mol和10^29.04 s^-1。 对NDT的热安全性进行了研究,获得NDT的自加速分解温度T_SADT为212.19 ℃,热点火温度T_be为213.52 ℃,热爆炸临界温度T_bp为214.95 ℃,绝热至爆时间范围在5.43~6.26 s。     

Thermal analysis of the extremely Nitrogen-Rich Solids BTT and DAAT

3,6-Bis(2H-tetrazol-5-yl)-1,2,4,5-tetrazine BTT and 3,3'-azobis(6-amino-1,2,4,5-tetrazine) (DAAT) are nitrogen-rich substances considered as new components for energetic applications like gas generators. Therefore, the thermal decomposition behaviour of BTT and DAAT was thermoanalytically characterized. Both substances decompose at surprisingly high temperatures of >200°C. The decomposition heats released belong to the highest ever measured for energetic materials under similar experimental conditions and are spread over a relatively narrow temperature range. The online monitoring of the decomposition gases reveals the decomposition pathway which is initiated by ring opening reactions of the tetrazole and tetrazine subunits. Subsequent reaction steps could be identified leading to a residue-free degradation of the C-N-backbone of BTT and DAAT. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermal Behavior and Thermal Safety of Nitrate Glycerol Ether Cellulose

The thermal behavior, nonisothermal decomposition reaction kinetics and specific heat capacity of nitrate glycerol ether cellulose(NGEC) were determined by thermogravimetric analysis(TGA), differential scanning calorimetry(DSC) and microcalorimetry. The apparent activity energy(E_a), reaction mechanism function, quadratic equation of specific heat capacity(C_p) with temperature were obtained. The kinetic parameters of the decomposition reaction are E_a=170.2 kJ/mol and lg(A/s^–1)=16.3. The kinetic equation is f(α)＝(4/3)(1–α)[–ln(1–α)]^1/4. The specific heat capacity equation is C_p=1.285–6.276×10^–3T+1.581×10^–5T²(283 KSADT), critical temperature of thermal explosion(T_b) and adiabatic time-to-explosion(t_Tlad). The results of the thermal safety evaluation of NGEC are: T_SADT=459.6 K, T_b=492.8 K, t_Tlad=0.8 s.     

Energetic calcium(II) complexes of 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)1,2,4,5-tetrazine: synthesis,crystal structure,and thermal properties

We synthesized two calcium salts of 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz): [Ca₂(BTATz)₂(H₂O)₈·6H₂O] (1) and Ca(BTATz)(phen)(H₂O)₅·4H₂O (2). Complexes 1 and 2 were characterized by elemental analysis, Fourier transform infrared spectrometry, and single-crystal X-ray diffraction. Structural analysis revealed that Ca(II) was present in different coordination structures in the two complexes. Complex 1 exhibited a symmetric octahedral coordination that included three nitrogens and five water molecules. Complex 2 formed an asymmetric seven-coordinate structure with calcium connected to nitrogen in BTATz and to oxygens. The thermal behaviors of 1 and 2 were characterized via differential scanning calorimetry and thermogravimetry–differential thermal gravimetry. The peak thermal decomposition temperatures of 1 and 2 was 557.39 and 573.86 K, respectively. The kinetic equations of the main exothermic decomposition reaction were also derived. Moreover, the thermal safety of the complexes was evaluated by calculating some important thermodynamic parameters, such as self-accelerated decomposition temperature, thermal ignition temperature, and critical temperature of thermal explosion. Results indicated that both complexes exhibit good potential as a propellant component.