Synthesis of 5-[(2-hydroxynaphthalen-1-yl)diazenyl]isophthalic acid and its application to electrocatalytic oxidation and determination of adrenaline,paracetamol, and tryptophan

In this study,Au nanoparticles/poly 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid film modified glassy carbon electrode(AuNPs/poly(NDI)/GCE) has shown excellent electrocatalytic activity toward the oxidation of adrenaline(ADR),paracetamol(PAC),and tryptophan(Trp).The bare glassy carbon electrode(GCE) fails to separate the oxidation peak potentials of these molecules,while the poly(NDI) film modified electrode can resolve them.Electrochemical impedance spectroscopy(EIS)indicates that the charge transfer resistance of the bare electrode decreases as 5-[(2-hydroxynaphthalen-l-yl)diazenyl]isophthalic acid is electropolymerized on the bare electrode.Furthermore,EIS exhibits enhancement of electron transfer kinetics between analytes and the electrode after electrodeposition of Au nanoparticles.Differential pulse voltammetry results show that the electrocatalytic current increases linearly in the ranges of 0.01-680.0 μmol L~1 for ADR,0.05-498.0 μmol L~1 for PAC,and 3.0-632.0 μmol L~1 for Trp;with detection limits(S/N = 3) of 0.009 μmol L~1,0.005 μmol L~1,and 0.09 μmol L~1 for ADR,PAC,and Trp,respectively.The proposed method has been successfully applied for simultaneous determination of ADR,PAC,and Trp in biological samples.     

Solvothermal Synthesis of Two Isomorphous Two-Dimensional Double Wave-like Vanadium,Coordination Polymers with Square Channels

While organic-inorganic hybrid vanadium oxides, polyvanadate clusters and vanadium complexes have been extensively studied^[1-3], the construction of microporous two-dimensional and three-dimensional vanadium coordination polymers by bridging organic ligands remains relatively unexplored^[4], and hence further model complexes are required to understand the coordination nature of vanadium. We report here two isomorphous vanadium coordination polymers formulated as[VO(DBOD)₂]X₂(DBOD=l,4-diazoniabicyclo[2,2,2] octane-l,4-diacetate, X=Cl or Br). Crystal structural analysis shows that they are the first examples of non-cluster-type vanadium coordination polymer constructed from VO₅ square-pyramidal units. DODB in μ₂-niode along[110] and[1-10] directions links two adjacent two vanadium ions,Which resulting in double wave-like two-dimensional layers with 36-memered saddle-shaped rings (ca. 12.0×6.2 Å) As can be seen from the three-dimensional stacking array (Fig. 1), the adjacent two layers stack in a crossed laminating fashion giving rise to approximate square channels (ca. 6.2×6.2 Å) along c-axis direction.     

PMBP与中性磷萃取剂对铽(Ⅲ)的协同萃取

本文研究了1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(PMBP)与丁基膦酸二丁酯(DBBP)或磷酸三丁酯(TBP)的氯苯溶液在硝酸介质中对铽(Ⅲ)的协同萃取。测得了萃合物的组成及其萃取平衡常数,讨论了萃合物的可能结构式及协同萃取机理。     

Keggin 型磷钨酸盐修饰碳糊电极传感多巴胺的研究

多金属氧酸盐作为一类阴离子簇合物,由于其结构的多样性和尺寸大小的可调变性,在电化学、催化和药学等领域引起了人们的广泛关注.本文制备了多酸Co(C₁₅N₆H₁₂)₂[PW₁₂O₃₈]·5H₂O（Co[PW₁₂O₃₈]）修饰碳糊电极并通过电化学阻抗谱、循环伏安法以及差分脉冲伏安法对多巴胺的传感性能进行了研究.对其制备条件和检测条件分别进行了优化.在优化条件下,制备的传感器对多巴胺具有良好的选择性和灵敏度的检测能力.多巴胺的线性响应范围为8.0x10^-6 mol·L^-1至3x10^-5 mol·L^-1,灵敏度为0.039 μA·(μmol·L^-1)^-1,检出限（S/N=3）为5.4 x10^-6 mol·L^-1. 制备的多酸修饰碳糊电极用于检测多巴胺表现出良好的稳定性和重现性,并且对抗坏血酸、尿酸等常见的干扰物质,具有良好的抗干扰性. 多酸修饰的碳糊电极制备过程简单方便,成本低,传感性能良好,对应用于电化学传感器检测多巴胺具备潜在的应用前景.      

1-丁基-3-甲基咪唑醋酸盐和水组成的混合电解液中三价铬电沉积铬的研究

本文在[BMIM]OAc-H₂O电解液中研究了Cr³⁺的电沉积反应. 经循环伏安研究表明,Cr³⁺的还原属于受扩散控制的分步还原过程, 即Cr³⁺ + e →Cr²⁺和Cr²⁺ + 2e → Cr⁰. 在40℃下通过Rendle-Sevcik方程计算得到Cr³⁺的扩散系数为1.2×10^-8 cm²/s. 采用计时电流法探讨了Cr的三维瞬时成核机理. 对沉积的铬镀层进行了XRD、SEM表征, 结果表明经600℃氩气保护下煅烧后的镀层由Cr和Cr₂O₃纳米球状颗粒聚集而成, 其平均粒径为0.48μm. 对40℃,-3.0V条件下所得镀层进行EDX检测,发现Cr与O的能级峰十分明显,其中Cr的质量分数为83.8%. 通过在[BMIM]OAc、[BMIM]BF₄和[BMIM]PF₆三种离子液体体系中电镀得到的Cr镀层质量的比较, 表明OAc-的确有利于Cr的电沉积.     

Two Pentavanadate-based Organic-inorganic Materials with Third-order NLO Properties

Two isolated organic-inorganic pentavanadate-based hybrids,[H2N(CH3)2]6.34[V^V(μ3-O)4V4^IVO5(SO4)4]·(SO4)0.67·(DMF)·[HN(CH3)2]1.66(1)and [(HN)2(CH2)2(CH3)4][V^V(μ3-O)4V4^IVO5(SO4)4][H2N(CH3)2]3@(DMF)@ [HN(CH3)2]0.5(2)(DMF=N,N-dimethylformamide)have been synthesized under solvothermal conditions and structurally characterized.In compound 1,three adjacent basic units form a triangle type cluster.The symmetric double-layer exists in compound 2.The study of the third-order nonlinear optical(NLO)properties for the two compounds demonstrates that the two-photon absorption(TPA)cross-section σ values of compounds 1 and 2 are 1372 and 1228 GM,respectively,indicating that both compounds may have potential application in optical field.     

线性扫描伏安法研究(Ⅰ)——微盘电极上准稳态可逆波方程式及其验证

本文报道微盘电极上线性扫描伏安法准稳态可逆波方程式,并成功地进行了验证,理论和实验结果十分符合。     

由苯胺二聚体电化学制备聚苯胺的形貌可控性初探

以苯胺二聚体（N-phenyl-p-phenylenediamine）为起始单体,在1 mol·L^-1高氯酸水-乙腈混合液中,玻碳电极表面电化学制备聚苯胺. 实验结果表明,苯胺二聚体单体的聚合电位比苯胺单体的低约0.2 V,并且其聚合物具有更高的形貌可控性. 苯胺二聚体单体浓度分别为1、5和10 mmol·L^-1时,采用分步恒电流法可分别制备出形貌均一的聚苯胺纳米粒子（粒径30 nm）、超长的纳米线（> 5 μm 直径50 nm）和大面积纳米片（4 μm × 2 μm × 30 nm）.     

超微环电极上稳态伏安曲线理论和验证

本文提出了超微环电极上稳态伏安曲线理论,用K₄Fe(CN)₆·KCl体系和超微金环电极(T_i=25.7μm,T₂=20.2μm)对理论进行验证,测得的伏安曲线与理论相符。     

Simultaneous Determination of Gold(Ⅲ) and Copper(Ⅱ) with Two-Way Stripping Voltammetry

The simultaneous determination of Au(Ⅲ) and Cu(Ⅱ) by atomic absorption spectrometry^[1,2], X-ray fluorescence^[3] and differential-pulse polarography^[4] have been reported. The apparatus used in spectrochemical analysis are complex and expensive. The method reported in reference^[4] involves a poisonous electrode-DME(dropping-mercury electrode) and unsatisfied performance with the detection limit. We had reported the determination of trace Au(Ⅲ) or Cu(Ⅱ) by a sensitive tripping voltammetry with solid electrode^[5], but there is no report about the simultaneous determination of trace Au(Ⅲ) and Cu(Ⅱ) by stripping voltammetry ever since.     

Electrochemical behavior and analytical detection of Imidacloprid insecticide on a BDD electrode using square-wave voltammetric method

A sensitive square-wave voltammetric method for the determination of Imidacloprid(IMD) was developed using electrochemically pretreated boron-doped diamond(BDD) electrode. Aqueous solutions were prepared with Confidor 200 SL as the commercial formulation of IMD. Sodium sulfate(Na_2SO_4) was used as supporting electrolyte. The influence of operating parameters, such as the p H of the medium, frequency, pulse amplitude, scan increment and the concentration of IMD was investigated. An irreversible cathodic peak, corresponding to the reduction of IMD is observed at 1.21 V(vs. SCE) and the electrode reaction was controlled by adsorption. Under optimized conditions, the square-wave reduction peak current was linear over the concentration range of(30–200 μmol L~(-1)) with a detection and quantification limits of 8.60 μmol L~(-1))and 28.67 μmol L~(-1)), respectively. The results were compared with spectrophotometry and HPLC methods under some conditions and found to be in good agreement.To investigate applicability to real samples, the proposed method was applied to the determination of IMD in plum juice.     

溶液中钪与草酸离子的配位作用

提钪工艺中常使草酸钪溶于过量草酸铵溶液中。但文献中有关钪与草酸离子配位作用的报导甚少。等用分光光度法测定了ScC₂O₄⁺配离子的稳定常数,而J·Stary则用分配法测定了SC(C₂O₄)₃^3-配离子的稳定常数,这些工作都没有对溶液中可能生成各级配离子进行研究。     

Dimerization of Incomplete Cubane-Type Mo3S4(DTP)3 Units Linked by Bridging α, ω-Dicarboxylate

Since the trinuclear molybdenum cluster compound Mo₃S₄(DTP)₃(μ-DTP)(L) (DTP=diethyldithiophosphate, L=loosely-coordinated ligand) was reported^[1],a large number of monomeric trinuclear molybdenum derivatives have been synthesized from it by its diverse substitution reactions^[2]. This reaction provides a useful route to design cluster complexes with specific functions. By the reaction with α, ω-dicarboxylates, we successfully synthesized the first oligomer containing two incomplete cubane-type[Mo₃S₄] cores formulated as[Mo₃S₄(DTP)₃(DMF)]₂[η²-μ-OOC(CH₂)₃COO-μ-η²]) whose molecule structure is as follows:     

Halide abstraction as a route to cationic molybdenum(IV) compounds: Crystal and molecular structure of [CpMoCI(MeCN)4][SbCl6]2 · MeCN

Treatment of CpMoC1₃(MeCN)₂ with SbCl₅ in acetonitrile solution provides the solvated cationic series [CpMoCl₂(MeCN)₃]⁺, [CpMoCl(MeCN)₄]²⁺ and [CpMo(MeCN)₆]³⁺ as hexachloroantimon(V)ate salts following sequential halide abstraction. Characterization follows from microanalytical and spectroscopic (IR, and ¹H NMR) data and, in the case of [CpMoCl(MeCN)₄][SbCl₆]₂ · MeCN, by X-ray crystallographic studies. The structure is disordered but individual cations contain a six coordinated pseudo-octahedral metal geometry in which the cyclopentadienyl ligand (regarded as unidentate) and the chlorine atom occupy axial positions with an equatorial array of four acetonitrile ligands.     

Electrochemical sensor for Cd2+ and Pb2+ detection based on nano-porous pseudo carbon paste electrode

An electrochemical sensor based on self-made nano-porous pseudo carbon paste electrode (nano-PPCPE) has been successfully developed, and used to detect Cd²⁺ and Pb²⁺. The results showed that the electrodes can quantitatively detect trace Cd²⁺ and Pb²⁺, and with satisfied limit of detection, which has great significance in electrochemical analysis and detection.     

Crosslinking Reaction in the Formation of Porous Clays

Clay minerals are a class of hydrous layer aluminosilicates of the so-called phyllosilicate^[1] family made up of two basic types of layers, the SiO₄ tetrahedral sheet and the Al₂(OH)₆[or Mg₃(OH)₆] octahedral sheet, many of which posses interlayer cations capable of exchanging reaction with other cations. The preparation of porous clays are based on this reactivity of exchangeable interlayer cations by using the intercalation of polycations such as Al₁₃⁷⁺ oligomers^[2] into the galleries of clay minerals to form a microporous materials^[3] Here we reported a study on the interlayered crosslinking of a 2:1 type montmorillonites with a hydrolysed polycations Al in the formation of porous clays. Na-montmorillonite gel (Na-mont, particle size<2 μ) were purified by using sedimentation of Na-bentonite fines (400 mesh, Zhejiang, China) and subsequent extensively washing to remove any soluble Na⁺. Hydrolysed polycations Al was prepared by NaOH hydrolysis of AlCl₃ solutions in a condition^[2] of OH/Al=2.0 and then aging at 70-90℃ for 4 h by the following process^[3].     

Structure and magnetic property of bimetallic hexanuclear cluster based on 5-chlorosalicylaldehyde oxime

The bimetallic hexanuclear cluster [Mn4Ni2O2（Cl-Sao）6.（CH3OH）8].10CH3OH （1） was synthesized. Single-crystal X-ray analysis reveals that 1 consists of two [Mn2Ni（μ3-O）（Cl-Sao）3] subunits linked together via two pairs of long Ni-O bonds involving two oximate oxygen atoms and two phenolate oxygen atoms. Each Mn and Ni center achieves six-coordination with axial methanol molecules. The spin centers of the Mnm and Niu ions exchange magnetic coupling through O2-, O-phenolate and -N-O- bridges. The magnetic properties of the cluster have been investigated.     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

Effect of presence of 18-crown-6 on the response of 1-pyrrolidine dicarbodithioate-based lead selective electrode

The lipophilic ammonium salt of 1-pyrrolidine dicarbodithioic acid (PCDT)[I] was introduced as a selective ionophore for a sensitive Pb-ion selective electrode. Also, the effect of immobilization of 18-crown-6 (CW), into the above membrane, on the electrode performance was discussed. The slope of the PCDT-based [I] electrode was (26–30 mV decade⁻¹), while it was (29-30 mV decade⁻¹) for (PCDT+CW)-based [II] electrode according to the doping time. The linear concentration ranges were (1×10⁻⁶–1×10⁻¹ M) and (5×10⁻⁵–1×10⁻¹ M) for electrode types [I] and [II] after one-day doping. The working pH ranges were (5.0–10.0) and (7.0–10.0) for electrode types [I] and [II], respectively. Most of the common cations were tested for the evaluation of the electrode selectivity with correlation to the ionic radii of the tested cations. Among them only Na⁺, Ag⁺ and Fe³⁺ were the real interference. Application of using the electrode for the determination of lead in lubrication oil samples was performed with RSD (0.86–1.03%). The obtained results were compared to those of an atomic absorption spectrophotometric method.     

二氧化钛纳米颗粒/还原氧化石墨烯修饰玻碳电极在对硝基苯酚检测中的应用

本文报道了用二氧化钛纳米颗粒（TiO₂NPs）/还原氧化石墨烯（RGO）的复合物修饰玻碳电极检测微量对硝基苯酚（4-NP）的电化学方法. 本研究用扫描电子显微镜（SEM）对该复合材料形貌进行表征,用循环伏安法和交流阻抗谱对该复合物电极的电化学性能进行检测,表现出良好的电化学特性,采用差分脉冲伏安法对4-NP进行微量检测,结果令人满意,这主要得益于TiO2NPs/RGO复合物对4-NP有较高的催化活性,其电流峰值与浓度呈较高的线性关系,DPV的检测范围为10μmol·L^-1 ~ 350μmol·L^-1,检测限为0.13 μmol·L^-1. 与其他报道的一些电化学传感器相比,该传感器检测范围大,检测限低,且工作稳定,成本低,分析简单快速,具有很好的应用前景.