苯乙炔吸附在金电极上的现场表面增强拉曼光谱研究

采用电化学现场表面增强拉曼光谱研究了苯乙炔在金电极上的吸附行为及表面反应过程. 负电位下拉曼光谱的变化表明, 苯乙炔分子的炔端碳与金属电极成键, 分子垂直吸附于金电极表面. 在所研究的负电位区间内, 分子在电极表面的吸附取向并未随电位发生改变. 电化学现场光谱研究表明, 苯乙炔分子随电位负移, 碳碳叁键被加氢还原. 通过对比苯乙烯的现场表面增强拉曼光谱发现, 在－0.6 V至－1.2 V的电位区间内, 苯乙炔经过中间步骤生成苯乙烯, 最终被完全加氢为苯乙烷.     

Fe（CN）^3—＼4—6在金电极上氧化还原过程的拉曼光谱研究

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。     

电极表面Ag(δ+)-NH_3络合物的表面增强拉曼散射效应

本文采用氧化还原循环处理电极首次得到Ag/0.1mol L~(-1)NH_3+0.1mol L~(-1)NH_4Cl体系中吸附在银电极上氨分子的表面增强拉曼散射(SERS)效应。按氨分子在电极表面上的吸附量为每平方厘米8×10~(15)计算,增加因子为1.2×10~5.谱峰强度及位置随电极电位改变。吸附氨分子的SERS谱与Ag(NH_3)_2~+的正常拉曼光谱类似。本文结果表明电极表面上存在Ag(δ+)络合物,它可能是SERS效应的活性中心,用这个概念可较好地解释本文实验结果。通过谱图分析给出了Ag(δ+)表面络合物的可能结构模式。     

2,2′-联吡啶与锌电极作用的表面增强拉曼光谱研究

利用表面增强拉曼光谱(SERS)对2,2′-联吡啶分子在锌电极表面的吸附进行了研究. 实验表明, 2,2′-联吡啶和锌电极有较强的相互作用, 2,2′-联吡啶和锌表面的氧物种存在竞争吸附, 起始电位较正时, 氧物种的吸附使2,2′-联吡啶吸附电位负移；起始电位较负时, 2,2′-联吡啶的吸附抑止氧物种的吸附, 使其吸附电位正移, 且相同电位下氧化种的吸附量大大减少. 同时当电极电位由正往负移时, 吸附在锌表面的2,2′-联吡啶会发生构型转化, 在－1.3 V下以顺式构型垂直吸附, 而当电位负移至－1.4 V时则以反式构型吸附；而电极电位由负往正移时, 在研究电位区间内2,2′-联吡啶都以反式构型吸附, 不存在构型的转化.     

苯在铑电极上吸附的表面增强拉曼散射光谱研究

利用成熟的电极处理方法成功地获得了苯在粗糙铑电极上电化学吸附的拉曼谱图.详细探讨了电极电位、电解质等因素对苯的电化学吸附的影响.结果表明,苯分子吸附到粗糙铑电极上后,表面拉曼谱图与纯苯本体谱图的差别很大,说明吸附后的苯分子在几何及电子结构上发生了巨大变化.苯分子可能以1,3-环己二烯的结构吸附于铑电极表面.     

铂钌电极上乙醇解离吸附与氧化行为的原位SERS研究

应用电化学循环伏安法和原位表面增强拉曼光谱研究了乙醇在Pt-Ru电极上的解离吸附与氧化行为,首次获得了酸性介质中乙醇在Pt-Ru电极上解离吸附的表面拉曼光谱.实验表明:乙醇在粗糙铂和Pt-Ru电极上均能自发地解离出强吸附中间体CO,而且在Pt-Ru电极上,强吸附中间体CO氧化的过电位比在粗糙铂电极上降低了约140mV.初步证实酸性介质中乙醇在Pt-Ru电极上的氧化遵从双途径机理.本研究结果说明,表面增强拉曼光谱技术能拓展到有实用价值的电催化体系.     

电极表面Ag(δ+)-NH3络合物的表面增强拉曼散射效应

本文采用氧化还原循环处理电极首次得到Ag/0.1 mol L~(-1)NH_3+0.1 mol L~(-1)NH_4Cl体系中吸附在银电极上氨分子的表面增强拉曼散射(SERS)效应。按氨分子在电极表面上的吸附量为每平方厘米8×10~(15)计算, 增加因子为1.2×10~5。谱峰强度及位置随电极电位改变。吸附氨分子的SERS谱与Ag(NH_3)_2~+的正常拉曼光谱类似。本文结果表明电极表面上存在Ag(δ+)络合物, 它可能是SERS效应的活性中心, 用这个概念可较好地解释本文实验结果。通过谱图分析给出了Ag(δ+)表面络合物的可能结构模式。     

电化学方法和表面增强拉曼光谱技术研究钴电极表面咪唑的吸附和缓蚀行为

利用电化学和表面增强拉曼光谱方法研究了咪唑和钴电极的相互作用. 分析并指认了不同电极电位下咪唑溶液中钴电极上的表面增强拉曼光谱(SERS), 发现随电极电位的变化, 在钴电极表面存在三种表面物种并且可以在一定程度上相互转化. 在较负电位(−1.2~−0.9 V)区间, 咪唑在钴电极表面以吸附物种为主, 随电位正移, 吸附取向由通过吡啶N垂直吸附逐渐向C2=N3双键倾斜; 在较正电位区间(−0.8~−0.7 V)内, 吸附咪唑的信号逐渐减弱乃至消失, 而钴和咪唑的络合物信号逐渐增强; 开路电位(−0.6 V)下出现很强的钴的氧化物谱峰. 同时, 文中比较了钴电极表面在空白溶液和加入咪唑后的溶液中的极化曲线, 发现咪唑对钴电极的缓蚀作用较为明显. 该研究结果表明, 联合表面增强拉曼光谱技术和电化学方法使得人们可以从分子水平上了解表面物种和电极表面间复杂的相互作用.     

铑电极上的表面增强拉曼光谱研究(英文)

本文简要介绍了将铑电极用于表面增强拉曼光谱 (SERS)研究的方法 .具有较强活性的铑电极可以通过对电极施加方波电流进行恒电流粗糙获得 .对模型分子吡啶进行的表面拉曼光谱研究表明 ,该电极具有很好的稳定性和可逆性 ,并且其表面增强因子可达 4 0 0 0 .在对铑电极上一氧化碳的氧化过程进行的拉曼光谱研究中同时检测到桥式和线型吸附的C O和Pt C振动的拉曼信号 .本研究表明铑电极可作为多用的SERS基底 ,拉曼光谱可作为界面研究的通用工具 .     

银电极上植酸钠/2-氨基-5-巯基-1,3,4-噻二唑混合自组装层的表面增强拉曼光谱和电化学研究

应用表面增强拉曼散射光谱(SERS)和电化学方法, 对银电极上2-氨基-5-巯基-1,3,4-噻二唑(AMT)和植酸钠混合自组装单层结构和缓蚀性能关系进行了研究. SERS光谱表明, 银电极表面形成AMT膜后, 再组装植酸钠分子能够弥合AMT膜的缺陷. 交流阻抗和极化曲线实验表明, 形成的混合自组装层比单一AMT自组装层表现出更好的缓蚀性能. AMT膜层的等效电路为R(Q(R(Q(RW)))); 混合膜层电路图为LR(Q(R(Q(R)))).     

AMT在青铜-柠檬酸体系中的缓蚀行为及其机理

用电化学方法、红外反射光谱法研究AMT(2-氨基-5-巯基-1,3,4-噻二唑)在青铜 -5％柠檬酸体系中的缓蚀行为和机理.结果表明,AMT能有效抑制青铜在柠檬酸中的腐蚀,属 混合型缓蚀剂.红外反射光谱表明,膜的最外层结构为Cu(Ⅰ)AMT,AMT中-NH2参与一价铜的络 合反应,环上离氨基最近的N参与配位. 缓蚀机理归因于成相膜的形成.     

The Synthesis of 2‐(Chromon‐2/3‐yl)‐3‐(5‐thione‐4‐hydro‐1,3,4‐thiadiazol‐2‐yl)‐4‐oxo‐thiazolidine

2‐Formylchromones and 3‐formylchromones as the first materials singly reacted with 2‐amino‐5‐mercapto‐1,3,4‐thiadiazole to give the corresponding Schiff bases, which on cyclocondensation with mercapto‐acetic acid in 1,4‐dioxane yielded target compounds named 4‐oxo‐thiazolidines. The structures of all the synthetic compounds were confirmed by elemental analysis and IR, ¹H NMR, LC‐MS (ESI) spectral data.     

AMT异构体互变机理的理论研究

用密度泛函理论(DFT)的B3LYP/6-311G(d, p)和Müller-Plesset微扰理论的MP2/6-31G(d)方法，优化了AMT(2-氨基-5-巯基-1,3,4-噻二唑)各种异构体和过渡态结构的几何构型，并对它们的电子结构、振动光谱和化学键性质进行了研究.还研究了AMT异构体的互变机理，提出了AMT异构体abcda的循环式互变途径.进一步完成了对AMT异构体成键方式的自然键轨道(NBO)分析.     

Synthesis of 1,4‐Bis[(3‐Aryl)‐s‐triazolo(3,4‐b)‐(1,3,4)thiadiazole‐6‐yl]benzenes

Some 1,4‐bis[(3‐aryl)‐s‐triazolo[3,4‐b]‐[1,3,4]thiadiazole‐6‐yl]benzenes are readily accessible in high yields by reaction of 3‐aryl 4‐amino‐5‐mercapto‐1,2,4‐triazole with p‐phthalic acid.     

Synthesis of Some Novel 3,6‐Bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole Derivatives

The cyclization of 1‐amino‐2‐mercapto‐5‐[1‐(4‐ethoxyphenyl)‐5‐methyl‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole which was synthesized from p‐ethoxyaniline with various triazole acid in absolute phosphorus oxychloride yields 3,6‐bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives 9a?j , and their structures are established by MS, IR, CHN and ¹H NMR spectral data.     

In(OTf)3催化下水相合成2-(3,4,5-三甲氧基苯基)-5-[(5-烷硫基-1,3,4-噁二唑-2-基)硫甲基]-1,3,4-噻二唑类衍生物

以2-巯基-5-(3,4,5-三甲氧基苯基)-1,3,4-噻二唑为原料,经醚化、酰肼化、闭环、硫醚化四步反应合成了10个2-(3,4,5-三甲氧基苯基)-5-[(5-烷硫基-1,3,4-噁二唑-2-基)硫甲基]- 1,3,4-噻二唑类衍生物。通过元素分析、IR、MS、1H NMR和 13C NMR对目标化合物进行了表征。采用In(OTf)3催化下40 oC水相合成目标化合物,具有反应条件温和、合成收率高、催化剂可循环使用等特点。     

5‐Mercapto‐1,3,4‐thiadiazole‐2(3H)‐thione: Synthesis and Structure of Alkylated Derivatives

The observed structure of 1,3,4‐thiadiazolidine‐2,5‐dithione (also known as 2,5‐dimercapto‐1,3,4‐thiadiazole) has been previously reported in three different tautomeric forms including —dithiol and—dithione. This report examines the relative stability of each form and also reports synthesis and characterization of the structures of mono‐alkylated and di‐alkylated forms of 5‐mercapto‐1,3,4‐thiadiazole‐2(3H)‐thione. The methods of X‐ray crystallography, NMR spectroscopy, and ab initio electronic structure calculations were combined to understand the reactivity and structure of each compound.     

Experimental and theoretical studies of media effects on copper corrosion in acidic environments containing 2-amino-5-mercapto-1,3,4-thiadiazole

Corrosion behaviour of copper metal in acid solutions (HCl, H₂SO₄ and H₃PO₄) containing 2-amino-5-mercapto-1,3,4- thiadiazole (AMT) was investigated experimentally and theoretically via gravimetric, potentio-dynamic and quantum electrochemical approaches. Similar behavior was observed for H₂SO₄ and H₃PO₄ media, and related to the nature of anions at metal/solution interface. With regard to HCl, however, the rate of corrosion was determined to be low at initial stages, but high later on using an auto-catalyzing mechanism. In the presence of AMT, the experimental studies revealed that this molecule was a good anodic-type inhibitor causing substantial changes in corrosion potential. Moreover, its adsorption obeys the Langmuir isotherm. The values of ΔG _ads were determined and correlated to the inhibitor powers. Finally, the influence of media (anions) on metal corrosion was also investigated from molecular point of view by calculations of the copper-anions interaction using density functional theory.     

Corrosion inhibition and performance evaluation on 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives

Using electrochemical impedance spectroscopy (EIS) and scanning electronic microscopy (SEM), this paper evaluated the inhibition effect of four 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives named 2,5‐diphenly‐1,3,4‐thiadiazole (DPTD), 2,5‐di(2‐hydroxyphenly)‐1,3,4‐thiadiazole (2‐DHPTD), 2,5‐di(3‐hydroxyphenly)‐1,3,4‐thiadiazole (3‐DHPTD), and 2,5‐di(4‐hydroxyphenly)‐1,3,4‐thiadiazole (4‐DHPTD) on silver strip corrosion in 50 mg/l sulfur–ethanol solution under room temperature. The experiments indicated that the inhibition efficiency increased with increasing inhibitor concentrations, and the increasing order was (4‐DHPDT) > (3‐DHPDT) > (2‐DHPDT) > (DPDT). Quantum chemical calculation was applied to correlate inhibition performances with their electronic structural parameters of thiadiazole derivatives. Molecular dynamics simulations (DFT) were used to optimize the equilibrium configurations of the inhibitor molecules on the silver surface and to investigate the molecular structure effect on the corrosion inhibition efficiency. The efficiency order of the investigated inhibitors, which was obtained by experimental results, was verified by theoretical calculations. Contact angle (CA) analysis was also carried out, and finally confirmed the existence of the adsorbed film which prevailed in addition of thiadiazole derivatives. CA analysis indicated that the film of n‐DHPTD (n = 2,3,4) was hydrophilic, owing to two hydroxyl groups in their molecular. The adsorption of these compounds onto silver strip from 50 mg/l S‐ethanol system obeys Langmuir adsorption isotherm, and it belongs to mixed‐type adsorption mainly dominated by chemisorption. Copyright © 2016 John Wiley & Sons, Ltd.     

AMT在铜表面形成保护膜的STM研究

5一氨基七一流基一1、3、各喀二隆（AMT不仅是一种有效的感光材料和分析试剂，同时作为重要的中间体被广泛应用于农药、医药生产中间，但作为铜腐蚀抑制剂的应用还远不如苯并三氯哩．实验表明［'－'l，AMT在酸性、中性及碱性介质中对铜及其合金均具有较好的缓蚀作用，经AMT处理