Synthesis, Crystal Structure and Electrochemical Properties of [Ni(phen)_3]·(m-nitrobenzoic acid)_2·(H_2O)

A new nickel(II) coordination complex [Ni(phen)3]·(m-nitrobenzoic acid)2·(H2O) was synthesized by self-assembly of m-nitrobenzoic acid, 1,10-phenanthroline and nickelous per- chlorate. It crystallizes in the monoclinic system, space group C2/c, with a = 2.4596(6), b = 1.2124(3), c = 1.9824(5) nm, β = 97.088(5)o, V = 5.866(3) nm3, Dc = 1.474 g/cm3, Z = 4, Mr = 1301.82, μ(MoKα) = 0.417 mm-1 F(000) = 2688, R = 0.0493 and wR = 0.1025. Structural deter- mination indicates that the nickel(II) ion is coordinated with six nitrogen atoms from three phens, giving a distorted octahedral coordination geometry. The cyclic voltametric analysis shows that the electron transfer in the electrode reaction is irreversible.     

Solvothermal Synthesis, Crystal Structure and Electrochemical Property of Complex [Co(p-MBA)2(2,2'-bipy)(H2O)]·(H2O)

One novel complex [Co(p-MBA)2(2,2'-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2'-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic, space group P-1 with a=0.70479(14), b=1.1211(2), c=1.6718(3) nm, α=103.806(3), β=90.795(3), γ=104.207(3)°, V=1.2399(4) nm3, Mr=512.41, Dc=1.373 g/cm3, Z=2, F(000)=532, μ=0.733 mm-1, R=0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2'-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported.     

Solvothermal Synthesis,Crystal Structure and Electrochemical Property of Complex [Co(p-MBA)_2(2,2′-bipy)(H_2O)]·(H_2O)

One novel complex [Co(p-MBA)2(2,2′-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2′-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic,space group P1 with a=0.70479(14),b=1.1211(2),c=1.6718(3) nm,α=103.806(3),β=90.795(3),γ=104.207(3)o,V=1.2399(4) nm3,Mr=512.41,Dc=1.373 g/cm3,Z=2,F(000)=532,μ=0.733 mm-1,R= 0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2′-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported.     

Hydrothermal Synthesis,Crystal Structure and Electrochemical Properties of Complex [Cd(phen)_3]·(ClO_4)_2·(p-MBA)_2·(H_2O)_2

One new cadmium complex [Cd(phen)3]·(ClO4)2·(p-MBA)2·(H2O)2 has been hydro-thermally synthesized by reacting p-methylbenzoic acid (p-MBA),1,10-phenanthroline (phen) and cadmium perchlorate. It crystallizes in the triclinic system,space group P1,with a=1.2809(3),b= 1.3431(3),c=1.3734(3) nm,α=84.259(4),β=71.603(3),γ=74.424(3)o,V=2.1594(8) nm3,Dc= 1.532 g/cm3,Z=2,F(000)=1008,μ=0.697 mm-1,R=0.0646 and wR=0.1648. The crystal structure shows that the cadmium ion is coordinated with six nitrogen atoms from three 1,10-phenanthroline molecules,forming a distorted octahedral coordination geometry. The result of electrochemical property analysis shows that the electron transfer in the electrode reaction is irreversible.     

Spectroscopic and Structural Study of the 1:2 Aluminium(III) Complex of Quercetin

Quercetin (3, 3’, 4’, 5, 7-pentahydroxyflavone) is one of the most common flavonols present in nature. The complexation of Al(III) by various flavonoids has been suggested to reduce the overload of aluminum in the diet, a metal which has been implicated…     

Infrared and Raman spectra of CuCl2·2(H,D)2O and K2CuCl4·2(H,D)2O. Vibrational modes,assignment and coupling of the water librations

The i.r. and Raman spectra of CuCl₂·2H₂O and K₂CuCl₄·2H₂O and of deuterated samples of these compounds are presented in the range 50–1700 cm⁻¹ at liquid helium, liquid nitrogen, and ambient temperatures. The spectra obtained are discussed and compared with the literature data in terms of both bonding structure of the water molecules and vibrational modes, assignment, intermolecular coupling, and combination bands of the H₂O, HDO, and D₂O librations. The i.r. and Raman bands of the librational modes of CuCl₂·2H₂O are very broad even at liquid helium temperature indicating orientational disorder of the water molecules.     

Electrochemical Behavior of Mn( Ⅱ ) in the Melt LiCkl-KCl-MgCl2-MnCl2

采用循环伏安和计时电位等电化学技术研究了Mn(Ⅱ)在LiCl-KCl-MgCl2-MnCl2熔盐体系中的电还原过程和Mg-Li-Mn合金的共沉积条件.结果显示,在LiCl-KCl-MgCl2-MnCl2熔盐体系中,Mn(Ⅱ),Mg(Ⅱ)和Li(Ⅰ)的还原电位分别为-1.14,-1.78和-2.19 V.Mn先析出,在钼电极表面沉积;Mg在Mn上欠电位沉积生成Mg-Mn合金;而Li在Mg-Mn合金上欠电位沉积形成Mg-Li-Mn合金.实验结果表明,Mn(Ⅱ)在熔盐中的还原电极过程受扩散控制.Mn(Ⅱ)在熔盐中的扩散系数约为10-5 cm2/s.运用XRD技术对恒电流电解制备的Mg-Li-Mn合金进行了分析,结果表明,Mg-Li-Mn合金中含有β-Li,α-Mg和Mn 3个相.     

Effect of the Halogen Dopant (F–, Cl–) on the Transport Properties of Proton Conductors Based on Ba4In2Zr2O11

Russian Journal of Electrochemistry - The effect of F– and Cl– doping on the transport properties of the proton conductor Ba4In2Zr2O11 was analyzed. The halogen-substituted phases were...     

Nature of the binding of a c(2×2)-CO overlayer on Ag(001) and surface mediated intermolecular coupling

We present a first-principles study of the nature of the binding of a c(2×2)-CO overlayer on Ag(001) and of the origin of CO-CO interactions upon adsorption. Electronic structural changes induced by molecular adsorption provide an interpretation for earlier X-ray photoemission valence band spectra of CO/Ag(001). Our results establish that CO chemisorbs on clean Ag(001) and follows the Blyholder model of donation and back-donation between CO and metal orbitals. We analyze the origin of the dispersion of the C-O stretch mode and attest that it is caused by the metal-CO coupling. Specifically, the coupling of CO to Ag, although the weakest of those between it and transition and other noble metals, greatly enhances the intermolecular force constants. We also find that the response of the charge density around CO is much stronger and of longer range when the molecule stretches than when it rigidly vibrates against the surface. This difference explains why the C-O stretch mode disperses while the Ag-CO stretch mode does not.     

Si／C复合材料电极首次嵌锂过程的电化学阻抗谱研究

采用球磨法制备了Si／C复合材料,X射线衍射（XRD）和扫描电子显微镜（SEM）测试结果显示Si／C复合材料中硅保持着良好的晶体结构且均匀的分散于炭黑基体中．充放电测试结果表明Si／C复合材料首次放电容量高达3393mAh／g,4周之后可逆容量均保持在1000mAh／g左右,表现出较好的循环性能．电化学阻抗谱测试结果显...     

电沉积Bi2Te3基薄膜的电化学阻抗谱研究

以不锈钢为基底,利用电化学沉积方法制备Bi2Te3基薄膜材料,并采用X射线衍射技术、电子探针微观分析等方法对薄膜进行结构和成分表征,通过电化学阻抗谱技术对不锈钢表面Bi2Te3的电化学沉积机理进行了初步探讨.结果表明Bi-Te和Bi-Te-Se体系具有相似的电化学沉积机理,即Bi3+和2HTeO+或H2SeO3首先被还原为Bi单质和Te或Se单质,然后Bi单质与Te或Se单质反应生成Bi2Te3基化合物,而Bi-Sb-Te体系中,2HTeO+首先被还原为Te单质,生成的Te再与Bi3+和Sb(III)反应生成Bi2Te3基化合物,三种体系的沉积都受电化学极化控制.     

Electrochemical Impedance Spectroscopic Investigation in Detecting 2,4‐dinitrophenylhydrazine Using Catalytic Effect of Copper at Glassy Electrode

This paper reports on the use of electrochemical impedance spectroscopy (EIS) allied to copper (II) for the determination of 2,4‐dinitrophenylhydrazine (DNPH) at glassy carbon electrode (GCE). The experiment measurements were carried out in methanol at a potential of 0.3 V versus Ag/AgCl. The Nyquist plots were modeled with a Randle equivalent circuit, by identifying the charge transfer resistance as the relevant concentration dependent parameter. These measurements show that the impedance spectra of DNPH increased by the formation of non‐electroactive compound produced from specific interaction between DNPH and Cu (II), which will block the electron‐transfer process of the redox probe. Therefore, the proposed methodology offers a detection limit of 4.0×10^?8 mol L^?1. The proposed methodology was satisfactorily applied to determine DNPH in industrial water samples.     

纳米TiO2膜电极的电化学阻抗谱

纳米TiO2膜电极的电化学阻抗谱;纳米TiO2膜;电化学阻抗谱;催化电极;异相氧化还原电对     

贮氢电极电化学阻抗谱及其数学模型

从分析贮氢电极的放电过程着手，建立了具有明显物理意义贮氢电极电化学阻抗谱的数学模型，以该数学模型为基础，讨论了与电极材料性质和电极荷电状态相联系的一些参数。     

电化学阻抗谱法测定固态聚合物电解质的本体电阻

采用电化学阻抗谱法,对阻抗谱中的聚合物电解质本体电阻（Rb）与膜厚（L）的关系和固体聚合物电解质/惰性电极间的界面阻抗随直流电压的变化趋势进行了研究.结果表明,阻抗谱中聚合物电解质本体电阻（Rb）含有一定的阻塞电极/聚合物电解质间的界面阻抗;由于界面双电层电容的变化,在直流电压0.15～3 V范围内,界面阻抗随电压的增大而减小.     

Electrochemical Impedance Spectroscopy of 3 MeV Nickel Implanted into Steel

ABSTRACT

Impedance spectroscopy was used to study the corrosion of a nickel implanted steel sample. The dosaye was 5 × 10¹⁵ ions/cm² and the energy of the nickel ions was 3 MeV. The data from a Simple Randies circuit (R_p and C_dl) were used to explain the corrosion changes observed in a NACE National Association of Corrosion Engineers) Brine solution (used to emulate geothermal brine conditions) at pH 2.0 and 25°C in an air saturated solution. Iron concentrations measured by Induction Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) were used to calculate corrosion rates at various time intervals. Impedance spectroscopy^1,2 is an electrochemical technique which can be used to monitor corrosion and to our knowledge it has not been applied to implanted materials.     

尖晶石LiMn2O4中锂离子嵌入脱出过程的电化学阻抗谱研究

运用电化学阻抗谱(EIS)研究了尖晶石LiMn2O4电极的首次充放电过程. 发现EIS谱高频区域拉长压扁的半圆是由两个半圆相互重叠而成的, 分别归属于与锂离子通过固体电解质相界面膜(SEI膜)的迁移和与尖晶石LiMn2O4材料的电子电导率相关的特征. 通过选取适当的等效电路, 对实验所得的电化学阻抗谱数据进行拟合, 获得尖晶石LiMn2O4电极首次充放电过程中SEI膜电阻、电子电阻和电荷传递电阻等随电极极化电位变化的规律. 根据研究结果提出了嵌锂物理机制模型.     

An Impedance Molecularly Imprinted Sensor for the Detection of Bovine Serum Albumin (BSA) Using the Dynamic Electrochemical Impedance Spectroscopy

A molecularly imprinted electrochemical sensor is successfully developed to detect bovine serum albumin (BSA) based on the dynamic electrochemical impedance spectroscopy (DEIS) instead of the traditional impedance spectroscopy. The sensor is prepared using chitosan and pyrrole as modified material and functional monomers, respectively, and the fast and real‐time characterization of molecular imprinting process can be obtained by DEIS. It is indicated that the removal and rebinding processes of BSA are closely related with the DEIS impedance under dynamic conditions, and the direct correlation between the resulting kinetic information and BSA concentrations can be established. As a result, the impedance changing rates in the initial 5 min of BSA adsorption are linear to the BSA concentrations ranging from 0.0001 to 0.01 ng mL^?1 and 0.01 to 1 ng mL^?1 with a detection limit of 5×10^?5 ng mL^?1 (S/N=3). In addition, the detection of BSA by DEIS does not require the system to be in equilibrium. The sensor also shows simplicity, high sensitivity, good stability and acceptable recovery in real samples, indicating its promising prospects in the fast and real‐time detection of proteins.     

Influence of the Nature and Structure of Polyelectrolyte Cryogels on the Polymerization of (3,4-Ethylenedioxythiophene) and Spectroscopic Characterization of the Composites

Conductive hydrogels are polymeric materials that are promising for bioelectronic applications. In the present study, a complex based on sulfonic cryogels and poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated as an example of a conductive hydrogel. Preparation of polyacrylate cryogels of various morphologies was carried out by cryotropic gelation of 3-sulfopropyl methacrylate and sulfobetaine methacrylate in the presence of functional comonomers (2-hydroxyethyl methacrylate and vinyl acetate). Polymerization of 3,4-ethylenedioxythiophene in the presence of several of the above cryogels occurred throughout the entire volume of each polyelectrolyte cryogel because of its porous structure. Structural features of cryogel@PEDOT complexes in relation to their electrochemical properties were investigated. It was shown that poly(3,4-ethylenedioxythiophene) of a linear conformation was formed in the presence of a cryogel based on sulfobetaine methacrylate, while minimum values of charge-transfer resistance were observed in those complexes, and electrochemical properties of the complexes did not depend on diffusion processes.