In-situ FTIR Spectroelectrochemical and Electrochemical Studies of Ferrocene and Derivatives at a Platinum Electrode

Redox mechanism of ferrocene, acetylferrocene, ferrocenyl cinnamenyl ketone at a platinum electrode was studied with cyclic voltammetry (CV) and in-situ Fourier transform infrared (FTIR) spectroelectrochemistry. The IR bands in the range of 2000-1000cm^-1 attributed to the stretching and ring vibrations of these materials show the main spectral changes in the processes.     

Electrochemical Studies on the Deposition of Neodymium in DMSO

IntroductionTherareearthsandtheiralloysarewidelyusedasmagnetic,ophcal,nuclear,andsuperconductingmaterials.IfsuchametalthinfilInwaspreParedbyelectrodeposition,thefimctionefficiencywouldbegreatlyborovedandtheaPplicationfieldshouldex-pandextensively.However,theelectrodepositionofrareearthfromaqueoussoluhoniscomPlicatedbythefactthathydrogenisevolvedbeforerareearthisdeposited.Thus,aProhcnonaqueoussolventssuchasddriethylformandde(DMF),dAnethylsulfoxide(DMSo),propylenecarbonate(PC),andformandde…     

Spectroscopic and Spectroelectrochemical Studies of Interaction of Nile Blue with DNA

ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｉｓｇｅｎｅｒａｌｌｙａｃｃｅｐｔｅｄｔｏｄａｙｔｈａｔｔｈｅｒｅａｒｅｔｈｒｅｅｋｉｎｄｓｏｆｂｉｎｄｉｎｇｍｏｄｅｌｓｆｏｒｓｍａｌｌｍｏｌｅｃｕｌｅｓｔｏＤＮＡ ,ｗｈｉｃｈｒｅｆｅｒｔｏｉｎｔｅｒｃａｌａｔｉｖｅｂｉｎｄｉｎｇ ,ｇｒｏｏｖｅｂｉｎｄｉｎｇａｎｄｅｌｅｃｔｒｏｓｔａｔｉｃｂｉｎｄｉｎｇ .Ｉｎｔｈｅｓｅｂｉｎｄｉｎｇｍｏｄｅｌｓ ,ｔｈｅｉｎｔｅｒ ｃａｌａｔｉｖｅｂｉｎｄｉｎｇｉｓｔｈｏｕｇｈｔａｓｔｏｂｅｔｈｅｓｔｒｏｎｇｅｓｔｂｉｎｄｉｎｇｂｅｃ…     

Copolymer Formation Between Two N‐Substituted Anilines—Electrochemical and Spectroelectrochemical Studies

Abstract

Electrochemical polymerization of diphenylamine, DPA with N‐methyl aniline, NMA was performed using cyclic voltammetry in a 4?M sulfuric acid medium. The electrochemical parameters representing the polymer deposition showed a strong dependence on the molar concentration ratios of DPA or NMA in the feed. In situ spectroelectrochemical studies were performed during the electropolymerization with different molar concentration feed ratios of DPA. The results reveal the formation of intermediates together with DPA and NMA units. Derivative cyclic voltabsorptograms (DCVAs) were deduced at the wavelength of absorbance corresponding to the intermediates and explained with redox characteristics in cyclic voltammogram. Results from cyclic voltammetry and spectroelectrochemical studies favor copolymer formation between DPA and NMA. Copolymers were prepared for different molar concentrations feed ratios of DPA and the composition of the monomer units in the copolymers were determined. Reactivity ratios of DPA and NMA were deduced using Fineman–Ross and Kelen–Tudos methods and correlated with the results from cyclic voltammetry and spectroelectrochemical studies.     

Electrochemical Studies on the Interactions of Dipyridophenazine Complex of Ruthenium and Herring Sperm DNA

Cyclic voltammetry (CV) and single-step chronocoulometry were used to study the interaction of [Ru(phen)2dppz]2 (phen=l,10-phenanthroline; dppz=dipyrido[3,2-a:2‘,3‘-c]phen-azine) with herring sperm DNA. The addition of DNA caused a diminution in the peak current and a positive shift in the peak potential of the complex of [Ru(phen)2dppz]2 . The 12 mV positive shift in the peak potential of [Ru(phen)2dppz]^2 indicates that [Ru(phen)2dppz]^2 binds 2.6 times more strongly to DNA than its reductive form. In addition, by using fluorimetric and UV-spectrophotometric methods and studies of denatured DNA and the effect of NaC1 solution, it was also found that the binding mode was intercalation. The decrease of peak current is proportional to the concentration of DNA, which can be applied to estimate DNA concentration.     

Electrochemical and Spectroscopic Studies on Interaction between Complex of Copper（Ⅱ） with Schiff Base Ligand and DNA

Introduction Deoxyribonucleicacid(DNA)isthemostim- portantgermplasmofmostorganisms.Thebind- ingofsmallmolecules,especiallytransitionmetal complexestoDNAandmolecularidentificationare importantresearchsubjectsinlifescience.There- searchontheinteractionbetweensmallmolecules andDNAhasbecomeafieldofgeneralinterest[1], becausethisisveryimportanttoexpoundtheac- tionmechanismofanticancerdrugs,theexternal selectionofdrugsandcarcinogenesisofcarcino- geniccompounds.Ithasbeenreportedthatmany metalcomp…     

Electrochemical and Spectroscopic Studies on Interaction between Complex of Copper(Ⅱ) with Schiff Base Ligand and DNA

The crystal structure of ( [CuL (H2O) 2 ] (ClO4) 2 · 2H2O, CuL) (L ＝ N- (5-sulfosalicylidene)-4' -bromoaniline) was determined by means of X-ray crystallography. The interaction between CuL and salmon sperm DNA in a 0. 1 mol/L HOAc-NaOAc buffer solution (pH 5.10) was investigated by cyclic voltammetry and UV-Vis spectroscopy. A couple of redox peaks of CuL in the cyclic voltammograms(CV) can be seen at the glassy carbon electrode. It was found that the peak current of CuL decreased significantly with a negative shift of the peak potential in the presence of DNA compared with that in the absence of DNA. In addition,the decreased absorbance of CuL was observed with increasing the concentration of DNA; the absorption spectrum of an ethidium bromide(EB)-DNA system inthe presence of CuL confirms that the binding mode of CuL to DNA is different from the intercalation of EB with DNA. All the experimental results indicate that CuL can bind to DNA by electrostatic binding and form a 1:1 association complex with a binding constant of 2.72×104 L/mol.     

Electrochemical and Spectroelectrochemical Studies on Electrooxidation Reactions of (TPP)Co~Ⅱ/NO_3~- System

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅＮＯ－３ｃｏｏｒｄｉｎａｔｉｏｎｒｅａｃｔｉｏｎｓｗｉｔｈ（ＴＰＰ）ＣｏⅡｗｅｒｅｃｈａｒａｃｔｅｒｉｚｅｄｕｓｉｎｇｔｈｅｔｅｃｈｎｉｑｕｅｓｏｆｃｙｃｌｉｃ－ｖｏｌｔａｍｍｅｔｒｙ（ＣＶ）ａｎｄｓｐｅｃｔｒｏｅｌｅｔ...     

Electrochemical Studies of the Recognition Interaction of Rhodamine B with DNA

The recognition interaction of rhodamine B (RB) with DNA was studied in pH 7.5 Britton-Robinson (B-R) buffer solution by electrochemical techniques. An irreversible oxidation peak at glassy carbon electrode was obtained at 0.92V (vs. SCE). After the addition of DNA into the RB solution, the peak current of RB decreased apparently without the shift of peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction standard rate constant ks of RB in the absence and presence of DNA were determined, which did not change, indicating that a non-electroactive complex was formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly.     

Spectroelectrochemical studies of [Mo(dtc)_4][Eu(dtc)_4] and [Mo(dtc)_4][Er(dtc)_4]

Redox and spectroscopic properties of the eight-coordination complexes of molybdenum and the rare-earth elements Eu or Er with N,N-diethyldithiocarbamate (dtc) were characterised by cyclic voltamrnetry and UV-visible absorption spectra.The complex cation [Mo(dtc)4]+ is more stable than the complex anions [Eu(dtc)4]-and [Er(dtc)4]-in redox processes,and possesses good redox reversibility.The electron transfer number,formal standard electrode potential in the redox process for the complex cation and its diffusion coefficients were obtained by in aitu spectroelectro-chemistry.     

钼和稀土的二乙基二硫代甲酸盐配合物的电化学研究

研究了N,N-二乙基二硫代甲酸根(dtc)作配体的双核配位化合物[Mo(dtc)₄][Ln(dtc)₄](Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho和Er)的氧化还原性质及其在电极过程中的电化学特性.     

Cations Insertion in Molybdenum Cluster Compounds: Electronic Structure and Electrochemical Study Using Cavity Microelectrode

Owing to the high lability of cations in the three-dimensional framework of K_1+x Mo₁₂S₁₄ (0 ≤ x ≤ 1.6), first-principles calculations and electrochemical methods have been carried out to study the insertion of cations in the empty channels of this compound. The cavity microelectrode that is a suitable electrode for powder material analysis has been used in voltammetric experiments. Results obtained for Li⁺, Na⁺, Rb⁺, K⁺, Cs⁺ and NH₄ ⁺ cations are presented and discussed.     

Electrochemical Preparation and Characterization of Neodymium Hexacyanoferrate and Its Application

A novel route for the fabrication of neodymium hexacyanoferrate (NdHCF) modified glassy carbon electrodes (GCE) was proposed. The morphological characterization of NdHCF was examined by scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). The performances of the NdHCF/GCE were characterized with cyclic voltammetry and differential pulse voltammograms (DPV). The modified electrode showed excellent electrocatalytic effect and high stability toward the electrochemical oxidation of dopamine (DA) in phosphate buffer solution (pH 5.5) with a diminution of the anodic overpotential of 155 mV. The anodic peak currents increased linearly with the concentration of DA from 5.0×10^?7 to 6.0×10^?4 M with a detection limit of 1.0×10^?8 M (S/N=3). The most important is that the modified electrode could be used for the determination of DA in the presence of an ascorbic acid concentration as large as 100‐fold that of DA. The proposed method was used to determine DA in DA‐hydrochloride injection and showed excellent sensitivity and recovery. The ease of fabrication, high stability, and low cost of the modified electrode are the promising features of the proposed sensor.     

曲线拟合分光光度法测定微量钼的研究

在表面活性剂ＯＰ存在下，钼与ＳＡＦ形成灵敏度很高的三倍络合物，本文研究了测定微量钼的最佳显色条件和消除干成的方法，应用在多种干扰离子共存时进行分光光度法的一种新的数学解析方法－拟合曲线分光光度法，根据最逼近样品吸收曲线的拟合曲线，计算混合体系微量的钼的含量，该方法具有准确度高，抗干扰能力强的特点，比经典的单波分光光度法测定有更大的适应性。     

Synthesis and Structure of a Neodymium Complex with the Nitrilotriacetate Ligand: [NdIII(nta)]n

A neodymium complex, [Nd(nta)]_n ( 1 ) (H₃nta = nitrilotriacetic acid) was synthesized and characterized by X-ray diffraction analysis. Compound 1 exhibits a three-dimensional network, in which the Nd^III ion is coordinated by one nitrogen atom and seven carboxyl oxygen atoms with dodecahedral coordination. One striking feature is that in the Nd coordination center there is no water ligand found.     

固态Nd化合物f-f跃迁的光声光谱研究

通过光声光谱对固态 Nd化合物的 f -f跃迁进行了研究。根据 Nd F3、Nd(sal) 3· H2 O和 Nd(sal) 3(phen) 2 的谱峰位置 ,计算了它们的电子云重排参数β、键合参数 b1/2 和 Sinha共价参数δ,表明三元配合物中钕离子形成键的共价程度最高 ,而 Nd F3中键的共价性最弱。通过光声支量表征了不同化合物中 Nd3+ 的 f -f跃迁光声强度的变化 ,证实了随着键的共价程度增加和配位数的增大 ,超灵敏跃迁强度显著增大     

H_3PMo_(12-n)WnO_(40)·xH_2O的电子光谱与电化学性质研究

系统地考察了H3PMo12 -nWnO4 0 ·xH2 O系列酸在不同溶剂中的电子光谱行为 ,结果表明 ,Mo Ob ,c Mo键在稀水溶液中断裂 ,而在乙醇溶液中能够稳定存在 ;W Ob ,c W键在极稀的水溶液中也能够稳定存在 ;在有机溶剂中所有酸的特征吸收峰均发生红移。电化学性质的研究表明 ,随着分子中钨原子取代数的增多 ,酸的氧化性降低 ,最高还原峰电位和分子中钨原子取代数之间存在一近似线性关系。     

Mo（Ⅵ）－N－苯甲酰苯基羟胺络合物的极谱催化波

本文研究了Ｍｏ（Ⅵ）与Ｎ－苯甲酰苯基羟胺（ＢＰＨＡ）络合物的极谱行为，讨论了六次甲基四胺（ＨＭＡ）在形成极谱电流时的作用。在ＨＡＣ－ＮａＡｃ介质中，Ｍｏ（Ⅵ）－ＢＰＨＡ络合物在单扫示波极谱上，于－０．４５Ｖ产生一灵敏的吸附催化波。当体系中引入ＨＭＡ时，该波大幅度地向负电位方向移动至－１．１４Ｖ，灵敏度约提高２倍，且使空白基线平滑，有利于波的测量。该波检测限达４×１０－９ｍｏｌ／Ｌ，线性范围０～４×１０－７ｍｏｌ／Ｌ，工作曲线通过原点。测定了天然水中的痕量钼，讨论了极谱电流的机理。