聚2,5—二甲氧基苯胺薄膜电极对氢醒的电催化作用

本研究了电化学方法制备的聚２，５－二甲氧基苯胺（Ｐ２５ＤＭＡｎ）薄膜电极对水溶液中氢醌的电催化作用，以及影响催化作用的主要因素。研究结果表明，在酸性较强的水溶液中，在较宽的浓度范围内（氢醌的浓度为１×１０＾－＾５－１×１０＾－＾２ｍｏｌ／Ｌ）均有很好的电催化作用。催化反应的动力学参数。这种修饰电极有很好的化学稳定性和电化学稳定性，是一种很有应用前景的修饰电极。     

聚苯胺薄膜修饰电极对抗坏血酸的电催化氧化

本文表明聚苯胺(PAn)薄膜修饰电极对水溶液中的抗坏血酸(AH_2)在较宽的pH范围和较宽的浓度范围内均有良好的电催化氧化作用, 为EC平行催化过程。利用旋转圆盘电极(RDE)进行了催化过程动力学分析, 求出了催化反应动力学参数。在抗坏血酸浓度10~(-2)～10~(-6) mol·L~(-1)范围内, 催化峰电流与AH_2浓度均成良好的线性关系, 且PAn薄膜修饰电极具有很好的稳定性, 有应用分析抗坏血酸的意义。     

化学修饰电极的研究 Ⅷ.聚乙烯二茂铁薄膜电极对抗坏血酸的电催化氧化

本文表明用旋转涂层法制备的聚乙烯二茂铁(PVFc)薄膜电极在水溶液和乙腈中,0.3～1.0V(vs.SCE)电位范围内均可呈现二茂铁(Fc)的氧化还原峰.PVFc薄膜电极对水溶液中的抗坏血酸(AH_2)在较宽的pH范围和较宽的浓度范围内均有良好的电催化氧化作用,为EC平行催化过程.利用旋转圆盘电极进行了催化过程动力学分析,求出了催化反应动力学参数.PVFc薄膜电极的稳定性和催化稳定性都较好.在AH_2浓度6×10~(-2)～6×10~(-6)mol/L范围内,催化峰电流与AH_2浓度呈良好的线性关系,有应用于分析AH_2的意义.     

锇-聚乙烯吲哚配合物修饰电极对肾上腺素的电催化氧化

研究了配位聚合物锇 -聚乙烯吲哚 [Os( bpy) 2 ( PVI) 1 0 Cl]Cl和 Nafion双层膜修饰玻碳电极的电化学特性 ,该膜对肾上腺素 ( EP)的电化学氧化有催化作用 ,在通常的生理条件下 ( p H7.0 ) ,催化电流与 EP浓度在1 .0× 1 0 - 6～ 8.6× 1 0 - 5 mol/L范围内呈良好的线性关系 ,相关系数为 0 .9987.Nafion膜排除了抗坏血酸( AA)的干扰 ,表现出较高的灵敏度、选择性及良好的稳定性 .该电极可在 +2 50 m V下进行 EP的安培法测定 .用旋转圆盘电极对电催化过程的动力学进行了研究 ,催化速率常数 kch为 3 .53× 1 0 3mol- 1 · L· s- 1 .在较高 EP浓度下 ,催化电流与浓度的关系表现出 Michaelis-Menten型响应 ,Michaelis-Menten常数 Km 为1 .4 7mmol/L.     

二茂铁/L-半胱氨酸修饰电极的电化学行为及电催化性能

利用配对试剂将二茂铁酰胺键合在L-半胱氨酸自组装单层膜(SAM)表面, 制成稳定的二茂铁/L-半胱氨酸修饰电极, 该电极在pH 7.0的磷酸盐缓冲液中有一对很好的氧化还原峰. 运用循环伏安法和交流阻抗谱详细研究了修饰电极的电化学行为, 测得电子转移系数为0.66, 表观电极反应速率常数为6.86 s-1. 该修饰电极对肾上腺素有很好的催化作用, 峰电流与肾上腺素浓度在2.0×10-7～1.0×10-5 mol·dm-3范围内呈现良好的线性关系.     

过氧化聚吡咯膜修饰电极检测肾上腺素研究

报道了肾上腺素(EP)在过氧化聚吡咯膜(OPPy)修饰电极上的电化学行为及其测定方法。过氧化聚吡咯膜(OPPy)修饰电极对EP的氧化还原具有良好的催化作用,并具有较高的选择性。在最佳实验条件下,EP的还原峰电流与其浓度在2×10-7~5×10-4mol.L-1范围内呈良好的线性关系,相关系数为0.999 9,检出限为8×10-8mol.L-1。将该电极应用于EP实际样品的测定,效果良好。     

单壁碳纳米管/聚合物修饰玻碳电极的电化学行为及酪氨酸的伏安测定

制备了一种新型的单壁碳纳米管复合聚对氨基吡啶(SWNTs POAP)修饰电极。研究了酪氨酸(Tyr)在该电极上的电化学行为。SWNTs POAP修饰电极对Tyr具有良好的电催化作用,氧化峰电流分别与Tyr的浓度在1.0×10-7～5.0×10-6mol L和6.0×10-6～6.0×10-5mol L范围内呈良好线性关系,检出限为5.0×10-8mol L。该电极具有良好的灵敏度、选择性和稳定性,可用于Tyr的测定。     

聚萘胺化学修饰电极对抗坏血酸的电催化研究(Ⅰ)

有关苯胺、苯酚类修饰电极前人做了大量工作,而对萘胺类物质的研究则相对较少.本文研究了萘胺聚合膜与过渡金属离子络合特性及其在碱性溶液中的电催化行为,发现聚萘胺薄膜经过渡金属离子处理后对某些氨基酸及抗坏血酸等有机酸的电氧化有催化作用,抗坏血酸浓度1×10~(-6)～1×10~(-4)mol/L范围内与催化电流值呈良好的线性关系.     

聚吖啶橙修饰电极上对苯二酚的电催化及分析应用

将吖啶橙修饰到玻碳电极表面,并研究了此电极上对苯二酚的电化学行为及其检测,发现聚吖啶橙修饰电极对对苯二酚有明显的电催化作用,使其氧化电位降低,峰电流增大。在优化的测试条件下,氧化峰电流与对苯二酚浓度在6.8×10-7~9.6×10-5mol.L-1和3.5×10-4~2.1×10-3mol.L-1范围内呈线性关系。在零电位处闭路富集130 s,测得其检出限为3×10-7mol.L-1,用于模拟废水样的分析,测得对苯二酚的回收率在97.3%~103.0%之间。     

聚对硝基苯偶氮间苯二酚修饰电极伏安法测定多巴胺

采用循环伏安法研究了多巴胺(DA)在聚对硝基苯偶氮间苯二酚(p-nitrobenzenazo resorcinol,简称NBAR)膜修饰电极上的电化学行为,用差示脉冲伏安法对多巴胺的含量进行测定.结果表明,聚NBAR膜修饰电极对DA有明显的电催化作用.在pH4.0的磷酸盐缓冲液中,氧化峰电流与DA浓度在5.0×10-6~8.0×10-4mol/L范围内呈良好的线性关系,检测限为6.0×10-7mol/L.修饰电极可有效消除针剂中其它组分对DA测定的干扰,已用于实际样品DA含量的测定,结果令人满意.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.