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1.
维生素K3电化学反应机理的红外光谱电化学研究   总被引:2,自引:0,他引:2  
用循环信安法及现场红外光谱电化学法研究了维生素K3在铂电极上,弱碱性水溶液介质中的电化学反应机理。循环伏安法实验结果显示VK3的电反应为两步电子准可逆电极过程,现场光谱电化学实验结果则从基团特征吸收频率的变化表明了VK3的电化学还原和氧化经历了从萘醌到萘酚的互变过程。据此进一步证实了VK3由萘醌到酚的电化学反应机理。  相似文献   

2.
合成了1-羟基-2-(1H)-吡啶硫酮及其甲基衍生物[AuL2]OH型配合物(L=PT^-,3-CH3-PT^-T 4-CH3-PT^-)。用元素,紫外光谱,外红光谱,^1HNMR谱,摩尔电导,TGDTA-DTG进行了表征,用循环伏安法研究其氧化还原性质,含甲基的配合物有较强的抑菌活性  相似文献   

3.
合成了1-羟基-2-(1H)-吡啶硫酮(HPT)及其甲基衍生物的[AuL2]OH型配合物(L=PT-,3-CH3-PT-和4-CH3-PT-).用元素分析,紫外光谱,红外光谱,1HNMR谱,摩尔电导,TG-DTA-DTG进行了表征,用循环伏安法研究其氧化还原性质,含甲基的配合物有较强的抑菌活性。  相似文献   

4.
以电化学循环伏安、现场ESR电化学以及现场薄层电化学方法研究了电生Co(I)TPP与溴代五己烷的反机制。在DMF中,Co(Ⅱ)/Co(Ⅰ)的氧化还原有明显的催化溴代环己烷还原的特片,反现场有自由基生成,反应产物之一是Co-C键化合物,可以在1.30V(SCE)-电子还原,当存在CH2-CHCN时,。生成另一种Co-C键化合物,该化合物在-1.10V(SCE)处一电子还原,证明溴代环己烷与Co(I)  相似文献   

5.
用循环伏安法和恒电流电解后的电位时间曲线法,研究了LiClKCl熔体中Nd3+和Ho3+在Mo电极上的电化学行为。结果表明,Nd3+和Ho3+在Mo电极上的还原都为一步3电子可逆过程。其扩散系数分别为:113×10-6和2142×10-5cm2·s-1(450℃),450℃下Ho3+/Ho电极对的标准氧化还原电位为2987V(vs·Cl/Cl-1),并讨论了实验值较理论值偏负的原因。  相似文献   

6.
1,4—二氢吡啶及其衍生物电化学反应机理的研究   总被引:6,自引:0,他引:6  
研究了11种1,4-二氢吡啶及其衍生物在乙腈溶剂中和铂盘电极上的电化学行为。实验结果表明:1,4-二氢吡啶及其衍生物在铂盘电极上的反应是受扩散和化学反应速率控制的两电子不可逆氧化过程,经连续两步失电子脱氢后形成相应的吡啶。用紫外吸收光谱电化学方法观测了电化学氧化过程。并与化学氧化产物的紫外光谱作了比较,证明1,4-二氢吡啶的电化学氧化产物与化学氧化产物一致。因此,电化学氧化是一种不需加化学试剂可使  相似文献   

7.
硼掺杂多晶金刚石薄膜电极的电化学特性   总被引:1,自引:0,他引:1  
朱建中  许春芳 《分析化学》1995,23(7):824-827
用循环伏安法和恒电位法研究了硼掺杂多晶金刚石薄膜电极(DFE)的若干电化学特性。电极面积4×4mm^2。在0.1mol/L KCl,NaNO3,NaOH和KH2PO4+Na2HPO4(pH=6.86)电解质溶液中电势窗口均为-500 ̄+800mV;而在0.1mol/L HCl和H2SO4溶液中电势窗口为-200 ̄+1100mV.K3Fe(CN)6的氧化峰电位为+500mV,与Pt电极测量相同;校正  相似文献   

8.
用循环伏安和红外光谱法对α-Fe2O3在室温LiOH溶液中的锂化行为进行研究,采用X射线衍射(XRD)、电感偶合等离子体光源的原子发射光谱(ICP)对α-Fe2O3电极在第一、二次循环中不同时段进行了跟踪分析测量。实验结果揭示:α-Fe2O3能进行少量锂化;大量的α-Fe2O3在第一次放电和充电后反应生成Fe3O4;之后,Fe3O4的锂化行不可避免地为Fe的析出,氧化反应所限制,但在用KOH作电解  相似文献   

9.
袁倬斌  邹洪 《分析化学》2001,29(10):1167-1169
光泽精与在肾上腺素自氧化体系中(pH=10.20)产生的超氧阴离子自由基反应,其氧化产物在 -1.16 V(vs.SEC)和-1.60V(vs. SEC)处有两个还原峰,其中-1.16 V处的还原峰是光泽精被氧化的中 间产物的双电子还原峰,-1.60V处的还原峰是最终产物 N-甲基吖啶酮(NMA)的双电子还原峰。形成 反应中间体和 NMA的反应是一级反应,其反应速度常数分别为 2.07× 10-4s-1和 2.23 × 10-5s-1。  相似文献   

10.
李念兵  陶长元 《分析化学》1998,26(10):1214-1217
应用掠射式椭圆偏振谱学方法和循环伏安法现场分析不同浓度K4「Fe(CN)6」不同浓度电解液在镀In2O3玻璃电极上进行的电化学反应,结果表明:当K5「Fe(CN)6」的浓度在1×10^-4-1×10^-3范围蛤,掠射式椭圆偏振参量Δ的峰值增量与其浓度成正比,而ψ的峰值增量与其浓度近似为指数关系。  相似文献   

11.
2,3—二氨基吩嗪的薄层光谱电化学研究   总被引:1,自引:0,他引:1  
焦奎  崔光磊  杨涛  牛淑妍 《化学学报》2003,61(4):514-519
研究了2,3—二氨基吩嗪(DAP)在金圆盘电极、金超微电极上的循环伏安行为 和在金网栅电极上的薄层循环伏安行为.在pH2.0的B—R缓冲溶液中的2,3—二氨 基吩嗪在金圆盘电极上为准可逆氧还过程;以超微电极法求得了2,3—二氨基吩嗪 在pH2.0的B—R缓冲溶液中的扩散系数,由耗竭性库仑电解和循环伏安法求得其电 极反应电子转移数和H+反应级数均为2,实验说明参与电极反应的H+也为2,并用循 环伏安法求得其标准电极反应速率常数.采用紫外—可见薄层光谱电化学方法测得 2,3—二氨基吩嗪的克式量电位和电子转移数,与电化学实验结果一致;双电位阶 跃—计时吸收紫外—可见薄层光谱电化学实验说明,2,3—二氨基吩嗪电还原无随 后化学反应,其在电极上经历了H+eH+e的两步一电子过程,生成产物2,3—二氨基 -5,10-二氢吩嗪.  相似文献   

12.
一种铂网栅薄层光谱电化学池的制作及表征   总被引:2,自引:0,他引:2  
焦奎  任立清  杨涛 《分析化学》2001,29(11):1299-1302
以铂网栅电极作工作电极,设计制作了一种应用于紫外-可见光谱电化学研究的新型光透薄层电化学池(OTTLE),并以铁氰化钾-亚铁氰化钾体系对此光谱化学池进行了表征。铁氰化钾-亚铁氰化钾体系在该池中有良好的循环伏安特性,并可获得良好的紫外-可见光谱。测得的克式量电位E^0,电子转移数n与文献结果一致。  相似文献   

13.
Ionic liquid,1-butyl-3-methylimidazolium acetate(BMImAc),was used in the electrochemical reduction of nitrobenzene.The electro-reduction of nitrobenzene on platinum electrode was studied by cyclic voltammetry(CV),in situ Fourier transform infrared(FTIR) spectroscopy and constant-potential electrolysis.The experimental results show that electrochemical reduction process of nitrobenzene was controlled by diffusion,the main reduction product was azobenzen at-1.45 V,and the influences of scan rate and temperature on the electrochemical behaviors were obviously.A reduction mechanism of nitrobenzene in an ionic liquid was a probable ‘nitrobenzene→nitrosobenzene→azobenzene→aniline' main reductive reaction route.  相似文献   

14.
Electroreduction of 4-amino-6-methyl-3-thio-1,2,4-triazine-5-one (I), 6-methyl-3-thio-1,2,4-triazine-5-one (II), and 2,4-dimethoxy-6-methyl-1,3,5-triazine (III) in dimethylformamide was investigated. Electrochemical techniques including differential pulse voltammetry (DPV), cyclic voltammetry (CV), chronoamperometry, and coulometry were employed to study the mechanism of the electrode process. From the analysis of the voltammetric and spectroscopic experiments a mechanism was proposed for the electroreduction of thio-triazine and triazine compounds. Compounds I and II having thiol groups exhibited similar redox behavior. Both compounds displayed two cathodic peaks, whereas the third compound (III), with no thiol group, showed only one cathodic peak in the same potential range as the second peak of compounds I and II.The results of this study show that in the former wave, the one electron reduction of thiol led to a dimer (disulfide) species and in the latter, the triazine ring was reduced in a two-electron process. The effects of various physical and electrochemical parameters were studied and the electrochemical behavior of the monomers was reported as a function of these parameters. A completely irreversible behavior was observed from cyclic voltammograms obtained under different conditions. Furthermore, in this study some numerical constants, such as diffusion constant, transfer coefficient, and rate constant of coupled chemical reaction were determined.  相似文献   

15.
《Electroanalysis》2003,15(3):208-218
The electrochemical oxidation and electrochemiluminescent behavior of homogentisic acid (HGA) has been studied in aqueous solutions over a wide pH range by linear sweep voltammetry, cyclic voltammetry, chronocoulometry at a glassy carbon electrode, by controlled potential electrolysis at a large area spectroscopic graphite electrode, and by spectroelectrochemistry at an optically transparent drilled holes graphite (DHG) electrode in a thin‐layer cell. The studies reveal that the electrochemical oxidation of HGA at carbon electrodes is a reversible process involving two‐electron, two‐proton transfer. In addition to the electrochemical oxidation, the chemical oxidation of HGA by dissolved oxygen was investigated by spectroscopic method combined with voltammetry. It was revealed that HGA is fairly stable in strongly acidic media but readily oxidized by dissolved oxygen in alkaline media giving rise to 1,4‐benzoquinone‐2‐acetic acid, the same product as that of electrooxidation of HGA. This oxidation product is stable in acidic, neutral and weakly alkaline media, but can further degrade in strongly alkaline media yielding oxalate as the final product. The electrochemiluminescent mechanism of HGA in the presence of Ru(bpy)32+ at a glassy carbon electrode was also investigated in detail, based on which a sensitive ECL method for determination of HGA was developed, and the detection limit was 3.0×10?8 mol L?1.  相似文献   

16.
应用长光程薄层电解池(石墨电极和铂片电极),使用循环伏安法(CV)和单电位阶跃计时吸收法(SPS/CA),研究了肾上腺在pH=2.5~7.0的McIlvaine缓冲溶液中电氧化生成肾上腺素红的反应机理,测定了表观速率常数kobs.结果表明:溶液pH值对肾上腺素的电氧化反应有很大影响,肾上腺素生成肾上腺素红的kobs随溶液pH值的增加而增大.  相似文献   

17.
The electrochemical reduction mechanism of ethidium bromide was first studied by spectroelectrochemistry. This reduction was proved to be a two-step process by cyclic voltammetry, differential pulse voltammetry and spectroelectrochemistry, in which each step was proved to be a one-electron transfer process by a spectropotentiostatic fluorescence technique. Hydroethidine was confirmed to be the final product by comparing the spectrum of the product of the electrochemical reduction to that of the product of the chemical reduction of ethidium bromide, and a carbon-centered radical was concluded to be a reasonable intermediate product during the electrochemical reduction of ethidium bromide.  相似文献   

18.
Copper oxidation in 1–10 M sulfuric acid solutions is studied using cyclic voltammetry and x-ray diffraction methods. Copper passivation is shown to be caused by the formation of a resistive porous layer of copper(I) oxide via an electrochemical mechanism. The primary product of the electrode reaction is unstable and, depending on the acid concentration, either enters chemical reactions with electrolyte components or is oxidized electrochemically to give copper(II) oxide.  相似文献   

19.
张环华  张克立 《应用化学》1999,16(3):100-102
以卟啉环为配体的金属卟啉配合物具有特殊的光、电、磁及生物功能.在卟啉骨架的吡咯环上引入拉电子基团如CN或Br等,能改变卟啉的氧化还原电位;当有PhIO、H2O2、NaOCl、RCO3H等氧化剂存在时,这类卟啉衍生物可作为有机环氧化的催化剂.因此对环取...  相似文献   

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