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1.
天然气与硫酸盐热化学还原反应的模拟实验研究   总被引:4,自引:1,他引:4  
为探讨天然气中高含量硫化氢形成的化学机制,利用高温高压反应装置,对天然气与固态硫酸钙反应体系进行了热模拟实验研究。使用气相色谱仪、微库仑仪、傅里叶变换红外光谱仪和X射线衍射仪对产物进行了分析,探讨了硫酸盐热化学还原反应的热力学特征,并进行了反应动力学研究。结果表明,高温下天然气与固态硫酸钙可以发生反应,产物主要为硫化氢、二氧化碳、碳酸钙、水和炭。热力学研究表明,天然气与固态硫酸钙的反应可行,升高温度对反应有利,同一温度下长链烷烃与固态硫酸钙发生反应的可能性要比短链烷烃大。根据动力学模型得到反应活化能为96.824kJ/mol。  相似文献   

2.
蒽醌是自然界中非常重要的一类醌类化合物,具有抗菌、抗癌、止血、防氧化等多种生物活性,受到药物学家及相关工作者的特别关注。本文综述了近年来这类化合物的合成方法,重点介绍了Friedel-Crafts反应、Michael 反应、Diels-Alder反应、Heck反应、羰-烯反应、蒽环氧化反应等在蒽醌骨架构筑过程中的研究进展。最后对这类方法中存在的问题进行了讨论,并对未来的发展进行了展望。  相似文献   

3.
化学振荡与生化、生理现象关系密切,有维生素C参与的化学振荡反应也很引人注目.赵学庄等对维生素C存在的B-Z反应的振荡行为与机理进行了研究.他们的实验表明,当加入维生素C时,B-Z反应的诱导期增长,振荡周期增大,振荡寿命缩短,与向反应体系加入等量的Br-所产生的影响是一致的,并由此推断,维生素C对B-Z反应的影响可能是由维生素C与BrO反应生成Br-抑制了此反应的化学振荡,据此,凡是能与BrO反应生成Br-的物质,其对B-Z反应的影响必将类似于维生素C,硫酸羟胺与水合肼就属于此类物质.本文初步研究了它们对B-Z反应的影…  相似文献   

4.
镍基催化剂上硫醇与异戊二烯硫醚化反应的研究   总被引:1,自引:0,他引:1  
肖招金  黄星亮 《分子催化》2005,19(4):280-284
在上流式气-液-固三相固定床微型反应装置上,对Ni/Al2O3催化剂上硫醇与异戊二烯硫醚化反应进行了研究,并考察了反应温度、压力、空速、临氢条件对催化剂二烯硫醚化反应性能的影响。结果表明,异戊二烯与硫醇在镍基催化剂的作用下,可以发生反应生成高沸点的硫醚化合物,反应温度和空速对催化剂二烯硫醚化活性有明显的影响,提高反应温度和降低空速有利于提高硫醇在二烯硫醚化反应过程中的转化率,在临氢反应条下,可以提高催化剂二烯硫醚化反应的活性和稳定性。  相似文献   

5.
一种高效、洁净的还原醛的新方法   总被引:3,自引:0,他引:3  
报道了在超临界CO2中,实现氢转移反应的新方法,这一方法以水为氢授体, 锌粉为电子授体,高选择性地还原对甲基苯甲醛为相应的醇,并初步研究了反应温 度、反应体系中CO2的压力、反应时间对还原反应的转化率的影响。  相似文献   

6.
二氧化硫脲对有机化合物的还原作用研究   总被引:4,自引:0,他引:4  
报道了在碱性醇水溶液中,二氧化硫脲对含有硝基、羰基及烯键的有机化合物的还原作用,研究了这些反应的反应条件、反应产物和反应机理。  相似文献   

7.
李琼  李永红  姜建文 《化学教育》2018,39(23):65-70
综述了目前甲烷与氯气的取代反应实验存在的问题,对实验装置进行了改进,采用正交实验设计对影响该反应的温度、光照条件、气体比例、光照距离等4个因素进行系统探究,对实验条件进行优化,找出了甲烷与氯气取代反应的最佳实验条件。  相似文献   

8.
对几种有机溶剂中猪胰脂肪酸催化的酯交换反应进行了研究,详细考察了反应温度、反应时间、反应物摩尔比、反应物中水含量和不同溶剂对反应性能的影响。结果表明:1.反应温度在313K左右时酶显示出最高催化活性。2.在实验条件下,反应进行72h后,转化率不再随反应时间的延长而变化,即反应达到平衡。3.酯/醇摩尔比的增大对反应转化率的影响较小。4.反应系统中水含量为0.5%-1.3%时,酶的催化活性最高。5.酶的催化活性随溶剂极性增大而降低。  相似文献   

9.
双羟基四配位硅单体的合成   总被引:10,自引:0,他引:10  
以无定型二氧化硅为起始原料,与乙二醇、氢氧化钾反应,生成高反应活性的 五配位硅钾化合物,并以此为原料与2-氯乙醇反应制备了双羟基四配位硅化合物 。探讨了不同反应条件(如温度、不同反应物摩尔比、催化剂等)对该反应的影响 ,并对合成的化合物做了红外光谱、核磁共振(^1H,^13C)、元素分析、能谱元素 分析等结构表征。  相似文献   

10.
以悬浮聚合法制得一系列高交联聚二乙烯苯树脂,通过改变反应试剂、催化剂、反应溶剂考察了聚二乙烯苯树脂进行亲电取代反应的规律.结果表明,聚二乙烯苯树脂可发生亲电取代反应,反应程度较低.聚(对-二乙烯苯)的反应程度高于聚(间-二乙烯苯).  相似文献   

11.
二氧化硫与戊烷的气相光化学反应研究   总被引:3,自引:0,他引:3  
Baclock等^[1]的研究表明,在SO2与烃的光化学反应体系中,单重态SO2通过系间窜跃转化为三重态SO2参与光化学反应,Penzhorn等^[2,3]的研究表明,在SO2与C4以下气相烃的光化学反应中有多种产物存在,产物的复杂性预示反应为自由基链反应。Smith等^[4]等认为体系中存在烃的逐步氧化,同时证明SO2与烷烃光化学反应中自由基链反应的重要性,文献报道的研究多以凝聚态产物为切入点^[5],为避免器壁对光化学反应的影响,本文以气相物质为研究对象,对挥发性烷烃中结构最简单的戊烷与二氧化硫的光化学反应的气相反应产物,反应机理和影响因素等进行了研究。  相似文献   

12.
用三原子模型的准经典轨线方法研究了Cl与C2H6(v=0,j)的反应。计算结果表明,反应产物HCl的角度分布基本上为各向同性,其振动分布处于基态,与实验结果相一致。对反应轨线的研究表明,该反应为一直接反应,而且反应碰撞在低及高的碰撞参数下的机理不一样,在低碰撞参数下反应碰撞是直接完成的,产物HCl以向后散射为主,转动基本上是冷的,但比高碰撞参数下的热。在高的碰撞参数下则生成短寿命的碰撞复合物,产物  相似文献   

13.
Thermokinetic research methods for irreversible and reversible reactions in the adiabatic calorimeter are proposed. Four reaction systems, including an endothermic reaction, have been studied with an adiabatic calorimeter and the validity of these methods is verified.  相似文献   

14.
The mechanism for initially divergent radical reactions reconverging to form a single product is studied using density functional theory calculations. The calculation results suggest that there are six possible pathways from reactants to products. The free energy barriers of the rate‐determining steps of each pathway are almost equal. Thus, different from usual reaction, the selectivity of this reaction is determined by the relative value of free energy barriers of the two competitive reactions, that is, cyclization and bimolecular trapping, rather than that of rate‐determining steps. In all reaction pathways, cyclization reaction is more competitive than bimolecular trapping reaction due to its low free energy barrier. In addition, the free energy barriers of bimolecular trapping reaction between Bu3SnH and reactants are all lower than that of NC? C6H11. However, Bu3SnH is not always suitable due to its large steric repulsion. © 2014 Wiley Periodicals, Inc.  相似文献   

15.
The potential energy surface for the reaction of furan and methyleneimminium cation with formation of a Mannich base has been studied using AM1 and PM3 semiempirical calculations. Nonspecific solvent effects were taken account of in the framework of the multicavity self-consistent reaction field approach. Characteristics of the reaction path elucidated for various media are discussed. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 67: 359–366, 1998  相似文献   

16.
Synthesis of some novel 3-alkylated indoles via an uncatalyzed Michael addition of indoles using three components in one-pot solvent-free conditions is reported. The mechanism was established by performing the reaction in two steps. The reaction was also studied in different solvents and an important solvent effect was noticed.  相似文献   

17.
利用傅立叶变换红外光谱(FMIR)研究了二氧化碳(CO2)共聚物果碳酸亚丙酯合成聚氨酯的反应动力学,讨论了不同温度的初期反应速率、反应常数和反应的活化能。该工作为选择合适的反应条件提供了依据,在理论上和实践上都有重要意义。  相似文献   

18.
The reaction Sc+(1D)+H2S→Sc+S+H2 is theoretically investigated by ab initio MO methods. Two possible reaction channels on the singlet potential surface (PES) and the reaction mechanism are examined and discussed. Three regions of the potential surface were studied, the molecular complex, the S‐H insertion products and the transition states for the reaction. In addition the singlet and triplet PESs of this reaction system are compared in an investigation the chemistry of excited electronic state. © 2001 John Wiley & Sons, Inc. Int J Quant Chem 82: 60–64, 2001  相似文献   

19.
The stereoselective Rauhut–Currier (RC) reaction catalyzed by a cysteine derivative has been explored computationally with density functional theory (M06‐2X). Both methanethiol and a chiral cysteine derivative were studied as nucleophiles. The complete reaction pathway involves rate‐determining elimination of the thiol catalyst from the Michael addition product. The stereoselective Rauhut–Currier reaction, catalyzed by a cysteine derivative as a nucleophile, has also been studied in detail. This reaction was experimentally found to be extremely sensitive to the reaction conditions, such as the number of water equivalents and the effect of potassium counterion. The E1cB process for catalyst elimination has been explored computationally for the eight possible stereoisomers. The effect of explicit water solvation and the presence of counterion (either K+ or Na+) has been studied for the lowest energy enantiomer pair (1S, 2R, 3S)/(1R, 2S, 3R).  相似文献   

20.
The reaction of indoles with dialdehydes was studied for the first time. Mild reaction conditions using glacial acetic acid led to two novel kinds of reaction products: one designated as alkyl chain‐connected tetraindoles and the other one as bis(indolyl)‐substituted cycloalkane indoles. The suggested reaction pathways are discussed. The indole substituents of the cycloalkane indoles were either trans or cis orientated depending from the alkyl chain length.  相似文献   

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