普利沙星与Co(phen)2+3及DNA间结合作用的电化学和光谱

利用电化学和紫外光谱法研究了邻菲咯啉合钴(Co(phen)2+3)与普利沙星(PLFX)及DNA间在pH=7.4的三羟甲基氨基甲烷-盐酸缓冲溶液中的结合作用. 紫外光谱测量结果表明,普利沙星与Co(phen)2+3发生了结合作用形成二元络合物,结合常数为2.0×104 L/mol. 电化学测量表明,在Co(phen)2+3-普利沙星络合物中加入DNA后,Co(phen)2+3-普利沙星络合物的峰电流下降,峰电位差增大了17 mV,式电位负移了3.5 mV,推断络合物与DNA作用方式主要为静电作用.     

普利沙星与C0(phen)2+3及DNA间结合作用的电化学和光谱

普利沙星与C0(phen)2+3及DNA间结合作用的电化学和光谱;     

用于DNA杂交检测的丝网印刷型生物传感器的研究

将单链DNA(ssDNA)固定到丝网印刷碳电极上构成电化学DNA传感器,采用电化学指示剂,建立DNA杂交的检测方法.Co(phen)33+电化学指示剂通过钴盐与配体邻菲罗啉络合制备,采用等离子发射光谱法(ICP-AES)和核磁共振法(NMR)表征功能基团,采用循环伏安法(CV)分析指示剂的电化学特性,并以此为基础研究ssDNA在电极表面的固定及DNA杂交过程.本研究探讨了直接吸附、静电吸附与键合等3种ssD-NA在电极表面的固定方法,结果表明,静电吸附法和键合法具有较高的ssDNA固定量,采用静电吸附法固定探针的电极杂交目标DNA后,Co(phen)33+易于嵌入双链DNA (dsDNA)中,CV峰电流(ip)信号随目标DNA浓度增加.本研究采用静电吸附ssDNA的电极检测DNA杂交,实验表明,当探针固定液中ssDNA浓度为5 mg/L时,目标DNA浓度在6.65×10- 8～4.26× 10-6mol/L范围内,Co(phen)33+在dsDNA修饰电极上ip值与DNA浓度呈良好的线性关系,R2为0.9819.本研究为建立新的微生物分子分型手段提供了初步依据.     

光谱法研究依诺沙星与铁(Ⅲ)及其DNA的相互作用

用荧光和紫外光谱法研究了依诺沙星(ENX)及其铁络合物与DNA的相互作用。Fe(Ⅲ)、DNA均能以静态猝灭的方式猝灭ENX分子的荧光。并且用荧光法测定了ENX-Fe(Ⅲ)和ENX-DNA二元络合物的组成和形成常数。ENX-DNA的光谱图在有Fe(Ⅲ)存在时,发生了明显的变化,表明能够形成ENX-Fe(Ⅲ)-DNA三元络合物?研究表明在一定的浓度范围内,三元络合物的荧光强度与天然DNA的浓度成线性关系。讨论了反应的最佳条件。进一步探讨了依诺沙星、Fe(Ⅲ)和DNA结合机理。     

旋转铂盘电极上Cu(phen)22+与6-巯基嘌呤的相互作用

在 Tris-NaCl(pH=7.2)缓冲溶液中,应用循环伏安法、微分脉冲伏安法、 旋转圆盘电极实验、交流阻抗法及其数据模拟等技术研究了Cu(phen)22+（phen=1,10-邻菲咯啉）与6-巯基嘌呤（6-MP）的相互作用.结果显示, Cu(phen)22+与6-MP无论在扩散控制过程或电化学控制过程都发生了相互作用. Cu(phen)22+及其与6-MP的作用产物于铂电极上均呈现一对氧化还原峰,但后者呈现的氧化还原峰负移,峰电流减小，交流阻抗结果显示,无论6-MP存在与否, Cu(phen)22+在交流阻抗谱上均呈现两个清晰的电容弧,但当6-MP存在时,电化学反应电阻和电化学吸脱附电阻均增大. Cu(phen)22+在不同转速下的阻抗拟合结果显示,随转速增大,电化学反应电阻和电化学吸脱附电阻均减小,双电层电容呈增大趋势,而吸脱附电容呈减小趋势;当6-MP存在时,仍然呈现此变化规律.     

Co(phen)2TATP3+与DNA在旋转金盘金环电极上的相互作用研究

在pH=7.2的Tris缓冲溶液中,利用旋转环盘电极法研究了金电极上Co(phen)₂TATP³⁺与DNA的相互作用,并根据扩散控制和电化学控制下得到的各种参数,对它们作用的模式进行了讨论.发现当一定量的DNA存在时,Co(phen)₂TATP³⁺的扩散系数、还原反应的传递系数和半波电位下的速率常数、还原产物Co(phen)₂TATP²⁺的收集系数和脱出率等都发生了较大幅度的减小.利用Co(bpy)₃³⁺进行比较研究表明,Co(phen)₂TATP³⁺与Co(bpy)₃³⁺在加入DNA后在收集系数和传递系数变化上存在较大的差异.     

邻菲罗啉-铜(II)-水杨酰胺配合物与DNA相互作用的研究及分析应用

采用紫外吸收光谱法、循环伏安法和微分脉冲伏安法研究了一种水杨酰胺多吡啶铜配合物[Cu(phen)(sa)](phen=1,10-邻菲罗啉,sa=水杨酰胺)与DNA的相互作用。紫外光谱法显示DNA的加入能引起配合物特征吸收峰的减色效应,表明了二者之间的相互作用。循环伏安实验表明配合物在玻碳电极上呈现一对准可逆的氧化还原峰;加入DNA后,配合物的峰电流减小,峰电位正移,表明二者可能通过嵌插方式发生作用。微分脉冲伏安法进一步表明[Cu(phen)(sa)]作为电化学探针,能在1.3×10-5～6.7×10-5moL/L DNA浓度范围内对DNA进行定量检测。将该铜配合物作为杂交指示剂应用于DNA传感器中对花椰菜花叶病毒的35S启动子基因(CaMV35S)相关DNA片段进行检测,结果显示该传感器对互补序列和非互补序列具有很好的识别能力。     

Fe(phen)32+与DNA作用的荧光光度法研究

为了考察金属配合物Fe(phen)32+与DNA 的作用模式, 应用荧光光度法对Fe(phen)32+与DNA及DNA-EB的作用进行了研究,结果表明Fe(phen)32+是主要以共轭平面插入形式与DNA作用的, 并计算出稳定常数等一系列热力学数据.     

核黄素与脱氧核糖核酸相互作用的电化学和光谱法研究

在实验条件接近人体生理环境的pH7.4的Tris-HCl缓冲溶液中,分别采用电化学方法、紫外光谱法及荧光法并利用中性红作电化学探针,研究了核黄素和小牛胸腺DNA的相互作用。随着DNA浓度逐渐增加,核黄素的峰电流减小,峰位正移;紫外光谱产生减色效应;核黄素的荧光发生猝灭以及核黄素和中性红竞争与DNA相互作用等,采用几种方法的实验结果都表明两者能发生嵌插结合;多种计算方法得到两者作用的结合位点数为1,结合常数达到105(mol/L)-1。     

铂电极表面生物素-亲和素固载单链脱氧核糖核酸的电化学传感器

通过直接吸附将亲和素固定在Pt电极表面,联于生物素标记的脱氧核糖核酸(DNA)探针,制备了电化学基因传感器,建立了Pt电极表面修饰单链脱氧核糖核酸(ssDNA)的方法。修饰电极与待测溶液中人工合成的转基因食品中常有的花椰菜花叶病毒35S启动子(CaMV35S)或根癌农杆菌终止子(NOS)DNA片段进行杂交,以邻菲罗林钴络合物[Co(phen)3^3 ]为杂交指示剂,循环伏安法测量,通过杂交前后指示剂峰电流的变化检测DNA杂交的量。研究了电极修饰、杂交反应及测量的适宜条件,在优化实验条件下,峰电流的差值与DNA杂交量之间有良好的线性关系,相关系数r=0．9996。杂交后的电极经热变性再生,可重复使用多次。     

Bis(tetramethylammonium), bis(tetrabutylammonium), and bis(tetraphenylarsonium) dihydrohexaoxoxenonates(VIII)

Bis(tetramethylammonium), bis(tetrabutylammonium), and bis(tetraphenylarsonium) dihydrohexaoxoxenonates(VIII) were obtained in an aqueous solution and in acetonitriie. The rate constants of their decomposition were determined.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 184–185, January, 1995.This work was carried out with financial support from the International Scientific Foundation (Grant REI 000).     

手性二噁唑啉吡啶铁和镍配合物的制备与表征

Tridentate bis(oxazolinylpyridine)(1) reacted with nickel chloride or ferrous chloride in anhydrous ethanol to form bis(oxazolinylpyridine) Nickel(Ⅱ) and Iron(Ⅱ) complexes. The stable solid complexes were characterized with IR， UV， MS， XPS and elemental analysis. No stable complexes were formed with bidentate bis(oxazoline)(2) ins- tead of bis(oxazolinylpyridine).     

Crystal Structures and Characterizations of Bis(pyrrolidinedithiocarbamato) Cu(II) and Zn(II) Complexes

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HCOO在Cu(110)、Ag(110)和Au(110)表面的吸附

采用密度泛函理论(DFT)以及广义梯度近似方法(GGA)计算了甲酸根(HCOO)在Cu(110)、Ag(110)和Au(110)表面的吸附. 计算结果表明, 短桥位是最稳定的吸附位置, 计算的几何参数与以前的实验和计算结果吻合. 吸附热顺序为Cu(110)(-116 kJ·mol-1)>Ag(110)(-57 kJ·mol-1)>Au(110)(-27 kJ·mol-1), 与实验上甲酸根的分解温度相一致. 电子态密度分析表明, 吸附热顺序可以用吸附分子与金属d-带之间的Pauli 排斥来关联, 即排斥作用越大, 吸附越弱. 另外还从计算的吸附热数据以及实验上HCOO的分解温度估算了反应CO2+1/2H2→HCOO的活化能, 其大小顺序为Au(110)>Ag(110)>Cu(110).     

Crystal Structures and Characterizations of Bis(pyrrolidinedithiocarbamato)Cu（Ⅱ） and Zn(Ⅱ） Complexes

The structures of [Cu (S₂CN (CH₂)₄)₂] (1) and [Zn₂(S₂CN‐(CH₂)₄)₄] (2) have been determined by X‐ray crystallography analysis. They are all isomorphous and triclinic, space group of P1^?, with Z = 1. The lattice parameters of compound 1 is: a = 0.63483(2) nm, b = 0.74972(3) nm, c=0.78390(1) mn, α = 75.912(2)°, β = 78.634(2)° and γ = 86.845(2)°; compound 2: a = 0.78707(6) nm, b=0.79823(6) nm, c = 1.23246(9) nm, α = 74.813(2)°, β = 73.048(2)° and γ = 88.036(2)°. The copper atom is located on a crystallographic inversion center and zinc atom lies across centers of symmetry. The Cu(II) ion has a square‐planar geometry while Zn(II) has a distorted tetrahedral geometry. The thermal gravity (TG) data indicate that no structural transitions in the two compounds were abserved and the decomposition products can adsorb gas. Also they all have a high thermal stability.     

Spectrophotometric study of Cd(II), Pb(II), Hg(II) and Zn(II) complexes with 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin

The reaction of 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin (TCPP) with Cd(II), Pb(II), Hg(II) and Zn(II) was studied spectrophotometrically and kinetics, equilibrium constants as well as photodecomposition of complexes were determined. It was verified that these metal ions with large radius accelerate the incorporation reaction of zinc into TCPP. On the basis of the mechanism and kinetics of this reaction, a sensitive method for the spectrophotometric determination of trace amounts of Zn(II) has been developed. The molar absorptivity of examined Zn-TCPP complex and Sandell's sensitivity at 423 nm were 3.5×10⁵ M⁻¹ cm⁻¹ and 18.3 ng cm⁻². The detection limit for the recommended procedure was 1.4×10⁻⁹ M (0.9 ng ml⁻¹) and precision in range 20-100 ng ml⁻¹ not exceeds 2.7% RSD. The proposed method applied for zinc determination in natural waters and nutritional supplement was compared with AAS results and declared value.     

Complexation studies of Cm(III), Am(III), and Eu(III) with linear and cyclic carboxylates and polyaminocarboxylates

Solvent extraction and potentiometric titration methods have been used to measure the stability constants of Cm(III), Am(III), and Eu(III) with both linear and cyclic carboxylates and polyaminocarboxylates in an ionic strength of 0.1?mol?L^?1 (NaClO₄). Luminescence lifetime measurements of Cm(III) and Eu(III) were used to study the change in hydration upon complexation over a range of concentrations and pH values. Aromatic carboxylates, phthalate (1,2 benzene dicarboxylates, PHA), trimesate (1,3,5 benzene tricarboxylates, TSA), pyromellitate (1,2,4,5 tetracarboxylates, PMA), hemimellitate (1,2,3 benzene tricarboxylates, HMA), and trimellitate (1,2,4 benzene tricarboxylates, TMA) form only 1?:?1 complexes, while both 1?:?1 and 1?:?2 complexes were observed with PHA. Their complexation strength follows the order: PHA～TSA>TMA>PMA>HMA. Carboxylate ligands with adjacent carboxylate groups are bidentate and replace two water molecules upon complexation, while TSA displaces 1.5 water molecules of hydration upon complexation. Only 1?:?1 complexes were observed with the macrocyclic dicarboxylates 1,7-diaza-4,10,13-trioxacyclopentadecane-N,N′-diacetate (K21DA) and 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N,N′-diacetate (K22DA); both 1?:?1 and 1?:?2 complexes were observed with methyleneiminodiacetate (MIDA), hydroxyethyleneiminodiacetate (HIDA), benzene-1,2-bis oxyacetate (BDODA), and ethylenediaminediacetate (EDDA), while three complexes (1?:?1, 1?:?2, and 1?:?3) were observed with pyridine 2,6 dicarboxylates (DPA) and chelidamate (CA). The complexes of M-MIDA are tridentate, while that of M-HIDA is tetradentate in both 1?:?1 and 1?:?2 complexes. The M-BDODA and M-EDDA complexes are tetradentate in the 1?:?1 and bidentate in the 1?:?2 complexes. The complexes of M-K22DA are octadentate with one water molecule of hydration, while that of K21DA is heptadentate with two water molecules of hydration. Simple polyaminocarboxylate 1,2 diaminopropanetetraacetate (PDTA) and ethylenediamine N,N′-diacetic-N,N′-dipropionate (ENDADP) like ethylenediaminetetraacetate (EDTA) form only 1?:?1 complexes and their complexes are hexadentate. Polyaminocarboxylates with additional functional groups in the ligand backbone, e.g., ethylenebis(oxyethylenenitrilo) tetraacetate (EGTA), and 1,6 diaminohexanetetraacetate (HDTA) or with additional number of groups in the carboxylate arms diethylenetriamine pentaacetato-monoamide (DTPA-MA), diethylenetriamine pentaacetato-bis-methoxyethylamide (DTPA-BMEA), and diethylenetriamine pentaacetato-bis glucosaamide (DTPA-BGAM) are octadentate with one water molecule of hydration, except N-methyl MS-325 which is heptadentate with two water molecules of hydration and HDTA which is probably dimeric with three water molecules of hydration. Macrocyclic tetraaminocarboxylate, 1,4,7,10-tetraazacyclododecanetetraacetate (DOTA) forms only 1?:?1 complex which is octadentate with one water molecule of hydration. The functionalization of these carboxylates and polycarboxylates affect the complexation ability toward metal cations. The results, in conjunction with previous results on the Eu(III) complexes, provide insight into the relation between ligand steric requirement and the hydration state of the Cm(III) and Eu(III) complexes in solution. The data are discussed in terms of ionic radii of the metal cations, cavity size, basicity, and ligand steric effects upon complexation.     

Synthesis and Characterization of Ni(II), Cu(II), Zn(II) and Cd(II) Complexes of a New Vic-Dioxime Ligand

In this study, 1,2-dihydroxyimino-3,7-di-aza-9,10-O-α-methyl benzal decane (LH₂) was synthesized starting from 1,2-O-α-methyl benzal-4-aza-7-amino heptane (RNH₂) and antichloroglyoxime. With this ligand, complexes were synthesized using Ni(II) and Cu(II) salts with a metal:ligand ratio of 1:2. However, the reaction of the ligand with salts of Zn(II) and Cd(II) gave products with metal:ligand ratio of 1:1. Structures of the ligand and its complexes are proposed based on elemental analyses, IR, ¹³C- and ¹H-NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA).     

Energy relationship and the polarization of C_(60) cage in the endohedral complexes (X@C_(60))

In this paper, we carry out the calculation on the system (X@C60)(X=Li, Na, K, Kb, Cs; F, Cl, Br, I), where the position of X changes along 5 typical symmetry directions. For the calculation of quantum chemistry we use EHMO/ASED method, for the calculation of molecular mechanics we use Buckingham potential (exp-6-1) function, and for the calculation of thermo-chemical cycle we use individually isolating the processes such as the structure variation, charge transfer and charge distribution, and their interactions etc. The calculation results show that (1) In the region of radius r≈0.2 nm of the Ceo cage, the potential field is nearly spherical; (2) Except for Li and Na, the systems are the most stable with minimum energies at the center of C60 cage. For Li and Na, the systems are the most stable with minimum energies at r≈0.16 nm and r≈0.13 nm, respectively. In view of the interactive region of chemical bonds, the interactions between X and the C60 cage do not belong to the classical chemical bonds; (     

Spectroscopic evaluation of Co(II), Ni(II) and Cu(II) complexes derived from thiosemicarbazone and semicarbazone

Co(II), Ni(II) and Cu(II) complexes were synthesized with thiosemicarbazone (L(1)) and semicarbazone (L(2)) derived from 2-acetyl furan. These complexes were characterized by elemental analysis, molar conductance, magnetic moment, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non-electrolytic nature. All the complexes are of high-spin type. On the basis of different spectral studies six coordinated geometry may be assigned for all the complexes except Co(L)(2)(SO(4)) and Cu(L)(2)(SO(4)) [where L=L(1) and L(2)] which are of five coordinated square pyramidal geometry.