共查询到20条相似文献,搜索用时 187 毫秒
1.
报道一种新型的适用于水和非水溶剂的反射式现场显微红外光谱电化学池。该池利用毛细管效应来克服显微池中溶剂挥发和除氧的困难,保证电解薄层能长时间保持浸润和良好的工作状态。安装了50μm直径的铂微盘工作电极,分别在水溶液和二氯甲烷溶液中,用Fe(CN)6^4-/3-和二茂铁体系进行了表征。 相似文献
2.
Fe(CN)^3—\4—6在金电极上氧化还原过程的拉曼光谱研究 总被引:1,自引:0,他引:1
用电化学现场表面增强拉曼光散射光谱研究了Fe(CN)^3-/4-6在金电极表面的氧化还原过程及吸附行为,结果表明,Fe(CN)^3-6相对于Fe(CN)^4-6能更强烈地吸会在金电极表面上,并通过配体CN^-的N端吸附在电极表面。 相似文献
3.
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
4.
偶合反应化学发光法测定痕量银的研究——K4Fe(CN)6—Luminol体系 总被引:5,自引:0,他引:5
将Ag(I)催化K4Fe(CN)6的水合反应与Luminol同Cu(CN)^2-4的化学发光反应相偶合,建立起一种新的灵敏测定痕量银的化学发光分析法,在所研究的优化条件下,该法测定银的选择性较好,检测限达到4.0×10^-13g/mLAg线性浓度范围为1.0×10^-12~1.0×10^-6g/mLAg对4×10^-11g/mLAg(I)溶液连续11次测定的RSD≤3.5%,用于环境水和岩矿中银的 相似文献
5.
用微电子平面工艺制备了带宽和边长分别为10、20、30μm的带形和正方形微电极阵列(BMEA和SMEA)。在K3Fe(CN)6溶液中研究了它们的电化学特性。边长为10μm的SMEA(工作电极总面积仅为9×10^-3mm^2)有最大的电流密度(12.1μA/mm^2)和最短的响应时间(5s)。同一硅片中任选5个SMEA其H2O2工作曲线的线性范围为0.1~5mmol/L,平均斜率为220nA/mmo 相似文献
6.
现场显微红外光谱电化学技术及超微铂盘电极的反射吸收光谱测定 总被引:1,自引:1,他引:0
本文阐述了一种新的光谱电化学技术-现场显微红外光谱电化学法的反射式方法的技术特点和优势,报告了一种适于水溶剂和非水溶剂的反射式现场显微红外光谱电化学池的设计,并首次在25um直径的超微铂盘工作电极上,对Fe(CN)^4-6/FE(CN)^3-6进行了现场显微红外光谱电化学的测量。 相似文献
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铁的单点络合滴定法研究 总被引:1,自引:0,他引:1
本研究了Fe^3+的单点络合滴定法,导出了定量关系式,比较了以铂电极为指示电极和以PVC膜四氯络铁(Ⅲ)阴离子电极为指示电极时电位测量的稳定性及所得的分析结果。在Fe^3+浓度为1.000×10^-3mol/L时,18次实验的平均值为1.02×10^-4mol/L,相对偏差小于1.7%;Fe^3+在5.0×10^3mol/L以上时,相对偏差小于0.1%;其浓度小于10^-3mol/L而大于5×1 相似文献
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10.
用氧化还原聚合物修饰多孔电极 总被引:1,自引:0,他引:1
对3种类型Nafion/Os(bpy)3Cl2修饰电极的研究结果表明,单位表观电极面积上中继体载量比为:乙炔黑粉末微电极(A):Teflon粘结的乙炔黑膜电极(B):平面玻碳电极(C)=10^3:10^2:1.A比B及C更容易在真实表面上形成花天酒地而均匀的修饰层而有利于层内的电荷传递。在A类电极基础上制行的葡萄糖酶电极在10mmol/L葡萄糖溶液中的响应电流密度高达4.6×10^-^4A/cm^ 相似文献
11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
12.
Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
13.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
14.
Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
15.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
16.
N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
17.
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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19.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
20.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献