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1.
以咪唑为原料,经硝化和溴化反应合成了抗炎药物中间体——2,5-二溴-4-硝基咪唑,总收率80.3%,其结构经1H NMR和IR确认。  相似文献   

2.
Zn(C9H6O5N2)·2H2O配合物热分解非等温动力学的研究   总被引:2,自引:0,他引:2  
石凤  王大庆 《结构化学》1999,18(6):443-447
合成了Zn(C9H6O5N2)·2H2O,用元素分析、红外光谱、摩尔电导对该配合物进行了表征。并用热重(TG)对其热分解机理进行了研究,推断出了该配合物第三步热分解的非等温动力学方程为: dα/dt= Ae- E/RT(1- α)。  相似文献   

3.
以2-甲基咪唑为原料合成2-(二硝基亚甲基)-4,5-咪唑烷二酮(1), 收率为33.9% (16.8%文献值), 首次采用低碳液态醇实现1的开环反应, 产物为FOX-7. 对反应条件进行了优化, 对比了甲醇、甲酸、氨水三种亲核试剂的开环效果, 开环试剂为甲醇时, FOX-7收率为94.6%, 高于文献值(87.4%). 研究了1的络合性能, 合成了1的甲醇加合物2并进行了结构表征. 对开环反应机理和乙二酰脲的形成机理进行了探讨.  相似文献   

4.
[Pb2(TNR)2(CHZ)2(H2O)2]4H2O的结构及热分解机理   总被引:1,自引:0,他引:1  
The coordination compound of [Pb 2(TNR) 2(CHZ) 2(H 2O) 2]•4H 2O was prepared by using the aqueous solution of carbohydrazide, lead nitrate and sodium styphnate. The molecular structure of [Pb 2(TNR) 2(CHZ) 2(H 2O) 2]•4H 2O(C 7H 13 N 7O 12 Pb, Mr=594.43) was determined by using a single crystal diffraction analysis .The thermal decomposition mechanism of the title compound was studied by TGDTG, DSC and IR techniques. The crystal belongs to monoclinic with space group P2 1/n.The unit cell parameters are as follows: a=0.64700(10)nm, b=1.6074(3)nm, c=1.4883(3)nm,β=97.42(2)°,V=1.5349(5)nm3, Z=2, DC=2.572g•cm -3 ,μ(Mo, Kα)=11.080cm -1 , F(000)=1128. R=0.0422, Rw=0.0735. The binuclear lead coordination compound is bridged by two carbohydrazide molecules. The molecule has a symmetrical center. TNR 2- ,CHZ and H 2O coordinate with the central ions simultaneously.  相似文献   

5.
用碳酰肼 (CHZ ,NH2 NHCONHNH2 )、硝酸铅和三硝基间苯二酚 (TNR ,斯蒂酚酸 )的水溶液制备 [Pb2 (TNR) 2 (CHZ) 2 (H2 O) 2 ]·4H2 O .采用单晶分析的方法测定它的分子结构 ,并用TG DTG、DSC和 IR相结合的技术研究它的热分解机理 .所得晶体属单斜晶系 ,P2 1/n空间群 .晶体学参数为 :a=0 .6470 0 ( 10 )nm ,b =1.60 74 ( 3)nm ,c=1.4 883( 3)nm ,β =97.4 2 ( 2 )° ,V =1.534 9( 5)n ,Z =2 ,DC=2 .572 g·cm- 3,μ(Mo ,Kα) =11.0 80cm- 1,F( 0 0 0 ) =112 8.最终偏离因子R =0 .0 4 2 2 ,Rw=0 .0 735.该配合物分子呈中心对称 ,两个羰基O原子形成两个氧桥 ,TNR2 - ,CHZ和H2 O同时参与了与中心离子的配位  相似文献   

6.
利用温度快速跃升傅立叶变换红外原位分析技术对3-硝基-1,2,4-三唑-5-酮铅盐的快速热分解反应动力学进行了研究。借助快速升温过程中Pt金属丝的控制电压变化曲线得到剧烈放热峰的诱导出现时间tx,利用tx值计算得到了快速热分解过程的动力学参数。在0.1 MPa氩气气氛,230~270 ℃实验温度范围内,3-硝基-1,2,4-三唑-5-酮铅金属盐的活化能Ea=94.0 kJ·mol-1,lnA=20.5。同时得到了该化合物快速热分解过程的近似吉布斯自由能变,熵变和焓变。该方法借助温度快速跃升技术,在模拟材料实际使用情况下计算得到其动力学参数,可用于含能材料燃烧模型的建立。  相似文献   

7.
在配合物的研究中,一类含N、S、O的中性分子具有作为电子给予体与过渡金属离子配位的能力,因而引起了生物学领域和热分析动力学研究者的兴趣[1-4]。2,4-二羟基二苯甲酮(简写作BP)具有多个配位原子,常用作高分子材料的紫外线吸收剂、光稳定剂和医药中间体等。目前对其研究较多的  相似文献   

8.
3,4-二硝基吡唑热分解及非等温动力学   总被引:4,自引:0,他引:4  
采用TG-DSC综合热分析的方法,对3,4-二硝基吡唑(DNP)的热分解和非等温动力学进行了研究。结果表明DNP的热分解分两阶段进行,并且在升温速率达到15K/min时才能明显区分。分别采用Archar微分法和Coats-Redfen积分法计算了DNP第一阶段热分解反应动力学参数:Ea=91.6kJ.mol-1,lnA=42.7s-1。最可能的DNP热分解机理为随机成核和随后生长机理,符合动力学机理函数Avrami-Erofeev方程,n=3。  相似文献   

9.
在低价钛试剂作用下,以四氢呋喃为溶剂,研究了2-(2-硝基苯基)咪唑与席夫碱的分子间还原偶联反应.结果发现席夫碱中C-N键的断裂优于其与硝基的偶联成环,生成了5,6-二氢化咪唑并[1,2-c]喹唑啉.  相似文献   

10.
2-对乙酰氨基苯基-4,5-二对硝基苯基咪唑的合成及性能   总被引:1,自引:0,他引:1  
咪唑化合物;非线性光学活性有机化合物;2-对乙酰氨基苯基-4;5-二对硝基苯基咪唑的合成及性能  相似文献   

11.
Thermal degradation of atrazine and its metabolites has been investigated using a thermogravimetric technique(TG) with the application of three types of crucibles: opened, Knudsen type and labyrinthtype, and non-isothermal DSC method, using hermetically closed and opened alumina sample pans. The great influence of decomposition conditions (the crucible type) on thermal degradation was observed. TG analysis showed that the degradation process of atrazine took place in three stages. The increase of amino groups in triazine ring increases the amount of non-volatile thermal degradation products by association. The presence of chlorine substituent facilitates the forming of products with low volatility. Hydroxyatrazine decomposes only in one stage process. The dealkylation process observed in hermetical sample pans (DSC) was two-stage and in open sample pans one-stage process. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

12.
The dehydration process of Co(II), Cu(II) and Zn(II) methanesulfonates was studied by thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) techniques in dynamic N2 atmosphere. The TG/DTG curves show that all of them contain four crystallization water molecules, which are lost in two steps. The peak temperature and dehydration enthalpies ΔH were measured from DSC curves for each compound. The effect of procedural variables on the TG and DSC curves was investigated. In this work, the procedural variables included heating rate, Al pan state (unsealed and sealed) and sample mass.  相似文献   

13.
The thermal decomposition of copper(II) acetate monohydrate was studied in air and nitrogen atmospheres by means of DTA-TG and SEM measurements. The kinetics of the thermal decomposition steps in air was studied by using isothermal and non-isothermal thermogravimetric techniques. The results are discussed in terms of various reaction interface models and different techniques of computational analysis of non-isothermal data. The activation parameters, calculated by using a composite method of integral analysis of non-isothermal data, revealed not only their independence from the heating rate and fractional reaction, but also a better correlation and agreement with the results obtained under isothermal conditions. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

14.
A polymeric blend has been prepared using urea formaldehyde (UF) and epoxy (DGEBA) resin in 1:1 mass ratio. The thermal degradation of UF/epoxy resin blend (UFE) was investigated by using thermogravimetric analyses (TGA), coupled with FTIR and MS. The results of TGA revealed that the pyrolysis process can be divided into three stages: drying process, fast thermal decomposition and cracking of the sample. There were no solid products except ash content for UFE during combustion at high temperature. The total mass loss during pyrolysis at 775 °C is found to be 97.32%, while 54.14% of the original mass was lost in the second stage between 225 °C and 400 °C. It is observed that the activation energy of the second stage degradation during combustion (6.23 × 10−4 J mol−1) is more than that of pyrolysis (5.89 × 10−4 J mol−1). The emissions of CO2, CO, H2O, HCN, HNCO, and NH3 are identified during thermal degradation of UFE.  相似文献   

15.
不同粒度高氯酸铵的热分解研究   总被引:10,自引:0,他引:10  
利用高压差示扫描量热法(PDSC), 热重法(TG), 固体原位红外联用法(Thermolysis/RSFT-IR)和热分析与质谱和红外联用法(Thermal analysis-MS-FTIR)研究了不同粒度高氯酸铵AP在1.0 MPa压强下和常压下的热分解过程, 提出了不同粒度AP可能的热分解机理. 研究结果表明, 不同粒度AP的高压和常压下的热分解历程存在明显的差异, 较大粒度AP的受热分解过程中存在明显的低温分解阶段和高温分解阶段, 小粒度的AP则仅存在明显的高温分解阶段. AP的分解气体产物主要包括NO2, NO, N2O, O2, H2O和HCl.  相似文献   

16.
This work describes the synthesis, IR and UV-Vis spectroscopic characterization as well the thermal behavior of the [NiCl2(HIPz)4]⋅C3H6O (1), [Ni(H2O)2(HIPz)4](NO3)2 (2), [Ni(NCS)2(HIPz)4] (3) and [Ni(N3)2(HIPz)4] (4) (HIPz=4-iodopyrazole) pyrazolyl complexes. TG experiments reveal that the compounds 14 undergo thermal decomposition in three or four mass loss steps yielding NiO as final residue, which was identified by X-ray powder diffraction.  相似文献   

17.
The thermal decomposition of the complexes Mg(Clac)2 (ron)2 ×3H2 O(I), Mg(Cl2 ac)2 (ron)2 ×3H2 O(II) and Mg(Cl3 ac)2 (ron)2 ×3H2 O(III), where Clac =ClCH2 COO- , Cl 2 ac =Cl2 CHCOO- , Cl 3 ac =Cl3 CCOO- and ron =3-pyridylcarbinol (ronicol) had been investigated in air atmosphere in temperature range 20–1000°C by means of TG and DTA. The composition of the complexes and the solid state intermediate and resultant products of thermolysis had been identified by means of elemental analysis and complexometric titration. The possible scheme of destruction of the complexes is suggested. The final product of the thermal decomposition was MgO. The thermal stability of the complexes can be ordered in the sequence: I<III<II. IR data suggest that ronicol was coordinated to Mg(II) through the nitrogen atom of its heterocyclic ring. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

18.
Thermal behavior of copper(II) 4-nitroimidazolate   总被引:1,自引:0,他引:1  
The thermal behavior of copper(II) 4-nitroimidazolate (CuNI) under static and dynamic states are studied by means of high-pressure DSC (PDSC) and TG with the different heating rates and the combination technique of in situ thermolysis cell with rapid-scan Fourier transform infrared spectroscopy (thermolysis/RSFTIR). The results show that the apparent activation energy and pre-exponential factor of the major exothermic decomposition reaction of CuNI obtained by Kissinger’s method are 233.2 kJ mol−1 and 1017.95 s−1, respectively. The critical temperature of the thermal explosion and the adiabatic time-to-explosion of CuNI are 601.97 K and 4.4∼4.6 s, respectively. The decomposition of CuNI begins with the split of the C-NO2 and C-H bonds, and the decomposition process of CuNI under dynamic states occurs less readily than those under static states because the dynamic nitrogen removes the strong oxidative decomposition product (NO2). The above-mentioned information on thermal behavior is quite useful for analyzing and evaluating the stability and thermal charge rule of CuNI.  相似文献   

19.
ZnSn(OH)6的热分解动力学   总被引:1,自引:0,他引:1  
用TG/DTG联用技术, 在2.5、5.0、10.0、15.0、20.0 K·min-1不同线性升温条件下, 研究了ZnSn(OH)6的热分解过程. 结果表明, 在氮气气氛下, ZnSn(OH)6在298-873 K范围内发生了一步分解. 其失重率与理论计算值相符. 应用非等温多重扫描速率法对热分解过程进行了动力学分析, ZnSn(OH)6在氮气中分解的活化能E=128.77 kJ·mol-1, 指前因子lg(A/s-1)=10.61, 机理函数为Mample单行法则.  相似文献   

20.
GV150526A is a novel 2-carboxyindole derivative, recently synthesized by GlaxoWellcome, which is used in treatment or prevention of CNS disorders resulting from neurotoxic damage. It has been prepared in three forms, F1, F2 and F3, having significantly different hydration/dehydration behavior and/or diffraction patterns. Here, we extend the thermal analysis of these polymorphs above 200°C, where all forms are fully dehydrated and the main thermal phenomena are decomposition and melting. Simultaneous TG/DSC measurements have been repeated in wet and dry nitrogen atmospheres over a wide range of heating rates. Form F3 displays a qualitatively different behavior relative to F1 and F2. This fact is interpreted as an evidence of a mechanism of decomposition which sets F3 apart from F1 andF2. The thermal data are summarized by simple heuristic equations and few ‘apparent’enthalpies. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

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