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1.
在pH为7.0的磷酸盐缓冲溶液中,用荧光光谱,紫外光谱,电化学及紫外光谱电化学等方法研究了铜配合物与6-巯基嘌呤,腺嘌呤的相互作用,结果表明,Cu(phen)^2+2和Cu(bpy)^2+3与6-巯基嘌呤,腺嘌呤发生了相互作用,但作用程度不同,根据荧光光谱实验数据计算出Cu(phen)2+3和Cu(bpy)^2+3与6-巯基嘌呤,腺嘌呤的配位比均为1:1,它们与6-巯基嘌呤作用的配位常数分别为2.  相似文献   

2.
张荧丽 《分析化学》1998,26(6):703-708
以光谱电化学和荧光光谱法证明了络合物Cu(phen)22+和Cu(bpy)22+与次黄嘌呤能发生络合作用并求出它们的络合比为 1.络合常数分别为 1. 21× 104 L/mol和 2. 32 × 104L/mol;相互作用的产物的光谱电化学性质发生了明显的变化,结合了次黄嘌呤后的 Cu(Phen)2+-HX和Cu(bpy)2+-HX在空气中氧化的动力学常数明显减小.这些相互作用的定量数据为铜络合物与DNA作用部位提供了重要信息.  相似文献   

3.
合成了3种以4,4'-联吡啶为桥联配体的三核环状Cu(Ⅱ)配合物[Cu_3(4,4'-bpy)_3·(phen)_3](ClO_4)_6·2H_2O(1)、[Cu_3(4,4'-bpy)_3](bpy)_3](ClO_4)_6·H_2O(2)和[Cu_3(4,4'-bpy)_3·(NO_2-phen)_3](ClO_4)_6·6H_2O(3)。经元素分析、电导、IR、电子光谱、ESR、磁化率等方法进行了表征,推定该配合物具有以4,4'-联吡啶为扩展桥的结构。利用Heisenberg模型求得交换参数J值为-0.23cm-1(1)和-0.90cm-1(3),表明配合物中金属离子间仅有很弱的反铁磁交换作用.  相似文献   

4.
合成了3种以4,4’-联吡啶为配体的三核环状Cu(Ⅱ)配合物[Cu3(4,4'-bpy)3.(phen)3](ClO4)6.2H2O(1),[Cu3(4,4'-bpy),(bpy)3](ClO4)6.H2O(2)和[Cu394,4'-bpy)3.(NO2-phen)3](ClO4)6.6H2O(3)。经元素分析,电导,IR,电子光谱,ESR,磁化率等方法进行了表征,推定该配合物具有以4,4’-联吡  相似文献   

5.
SpectroelectrochemicalStudiesontheInteractionsofComplexesofCu(phen)2+2andCu(bpy)2+2withDNAZHAOGuang-chao,ZHUJun-jieandCHENHon...  相似文献   

6.
本文合成和表征了四种新的三核铜(Ⅱ)配合物)Cu(L)2,Cu(CH3-ebo)(clO4)2(CH3ebo表示1,2-亚丙基双(草酰胺根),L表示1,10-菲咯啉(phen)(1),5-diegad -1,10-adjdktk kssy(NO2-phen)(2),2,2'-联吡(bpy(3)和4,4-二甲基-2,2-联吡啶(me2bpy)(4).测定了四种配合物的变温磁化率*77-300K),求  相似文献   

7.
运用 pH电位滴定法,在 25±0.1℃ T, I=0.1(KNO_3)条件下,研究了 Cu(Ⅱ)与三吡啶胺(L’)和队(2’-羟基苄基)-二乙二胺(HL~2)的配位行为。结果表明,L’以二齿的形式和 Cu(Ⅱ)形成稳定的 2:1(L: M)配合物。其配位水分子的离解常数 p Ka为 7.54。对于 HL~2,三个氮原子和酚氧负离子与 Cu(Ⅱ)配位,酚羟基离解常数 p Ka为4.44。在25±0.1℃,I=0.1(KNO_3)条件下,pH=6~9(50mol·L~(-1))范围内,用紫外、可见分光光度法研究了L~1的Cu(Ⅱ)配合物催化对-硝基苯酚乙酸酯(NA)水解动力学行为,发现配合物催化NA酯水解反应速率常数k_(NP)与溶液 pH呈 Sigmoidal型曲线, k_(NP)最大值为 2. 53×10~(-2)L· mol(-1)· s(-1)。说明 L~1的 Cu(Ⅱ)配合物中的 Cu(Ⅱ)-OH~-是有效的亲核试剂,对底物NA酯的水解有较好的催化作用。  相似文献   

8.
在不同的温度下,考察了六氰合铁(Ⅱ)配阴离子[Fe(CN)6]4-还原trans-[Co(en)2(ImH)2]3+的反应动力学。结果表明,反应遵循H.Taube所提出的外配位界电子传递机理。在25℃,I=0.5mol·L-1,trans-[Co(en)2(ImH)2]3+/[Fe(CN)6]4-反应体系的前驱配合物离子对形成常数为Q1p=98.9mol-1·L,电子转换速率常数为Ket=1.3×10-4s-1,电子转移过程活化焓ΔH≠et和活化熵ΔS≠et分别为141.2kJ·mol-1、573.5J·mol-1·K-1。  相似文献   

9.
张淑敏  赫春香 《分析化学》2001,29(10):1147-1149
用单扫描极谱法研究了槲皮素(Qu)与Cu2+形成络合物的条件及反应机理。在 pH 8.50的磷酸盐缓冲溶液中,槲皮素与 Cu2+络合并在-0.59 V(vs.SCE)处产生一个灵敏的还原峰,其峰高与 Cu2+浓度在 4.0 × 10-6~1.8 × 10-5mol/L范围内呈现良好的线性关系,检测限为 3.0 × 10-6mol/L。测得络合物组成Cu2+:Qu=1:2,表观稳定常数为2.10× 1011。  相似文献   

10.
本文合成新试剂N-间甲苯基-N′-(氨基对苯磺酸钠)硫脲(MMPT),经红外、紫外、核磁、元素分析等测试,确定其结构。研究测定了试剂与40多种离子的反应及其配合物的表观摩尔吸光系数,它可作为Cu2+(m=0.015μg,c=0.5μg/mL)、Ag+(m=0.1μg,c=3.3μg/mL)的新鉴定试剂和光度法测定Pd2+(ε309.7=6.32×104L·mol-1·cm-1)、Pt(Ⅳ)(ε754.4=8.58×104L·mol-1·cm-1)等的显色剂,方法灵敏度高、选择性好,用于阳极泥、人发、矿石及催化剂中上述元素的鉴定或测定,均获满意结果。  相似文献   

11.
Silica gels doped with Cu2+ ions were prepared from the (3-aminopropyl) trimethoxysilane (APTMOS)/tetraethoxysilane (TEOS) systems. Sols showed a broad absorption peak at 640 nm, suggesting 3–5 coordination of the aminopropyl groups to Cu2+. For gels prepared from APTMOS and dried at room temperature, the 640 nm peak decreased and a red-shifted absorption appeared below 400 nm within a few months. The luminescence spectra of the xerogels showed emission bands at 430–470 and 510 nm. The former and latter bands are ascribed to Cu+ monomer and dimer emissions, respectively. These results indicate that Cu2+ ions are reduced to Cu+. When xerogels were prepared from APTMOS/TEOS = 1 (vol/vol), the color of xerogels was blue with an absorption peak at around 670 nm, indicating no reduction of Cu2+ ions.  相似文献   

12.
Summary Copper(III) and total copper in superconducting Y-Ba-Cu oxide and related compounds can be determinated by two successive iodimetric titrations after the sample has been dissolved under Ar in HCl/KI medium. First, the iodine equivalent to copper(III) ist titrated with Na2S2O3 solution at pH 4.8, copper(II) being masked with EDTA. The total copper is then determined in the same solution by demasking with acid and iodide, followed by iodimetric titration. The method is both accurate and reproducible. The relative standard deviations for 1.074% copper(III) and 23.37% total copper are 0.8% and 0.3%, respectively.  相似文献   

13.
The water-soluble Cu+chelator bathocuproine disulfonate (BCS) is widely used to quantify Cu+ or detect Cu+ formation in Cu2+-initiated oxidation reactions. The dichlorofluorescin (DCFH) assay is commonly used to monitor free radical reactions, reactive oxygen species (ROS), or reactive nitrogen species (RNS). Upon oxidation the non-fluorescent DCFH is converted into the fluorescent compound dichlorofluorescein (DCF). In the present communication we show that the Cu+ reagent BCS strongly facilitated the oxidation of DCFH in the presence of Cu2+ or Cu+. In contrast, 2,2′-dipyridyl (DP), which is also a Cu+-complexing reagent, but not as well known and therefore not as commonly used as BCS, did not cause any oxidative modification of DCFH in the presence of Cu2+ or Cu+. We therefore recommend that DP should be used instead of BCS to complex Cu+ in reactions which are initiated by Cu2+ and when ROS/RNS are analyzed by the DCFH oxidation assay.  相似文献   

14.
The first Alkaline Alkaline-Earth Oxocuprate (II, III): NaBa2Cu22+Cu3+O6 The compound NaBa2Cu3O6 was prepared by heating of Na2O2, BaO2, Cu2O in closed Ag-tubes. X-ray single crystal investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.4229; b = 11.4418; c = 14.4063 Å; Z = 8. Cu2+ and Cu3+ show square planar polygones of four and Na+ trigonal prisms of six O2?. The two barium point positions show coordination numbers C.N. = 8 and 6 + 4. The crystal structure is discussed.  相似文献   

15.
Spectral methods have been used to study the complexation of apple pectin modified with organic pharmacophores (nicotinic, salicylic, 5-aminosalicylic, or anthranilic acid) with Cu2+, Co2+, and Mn2+ ions in an aqueous solution. The composition and stability series of the metal complexes, corresponding to the empirical Irving–Williams series, have been established. The standard thermodynamic parameters (ΔH°, ΔG°, and ΔS°) of the complexation process have been calculated. It has been shown by means of 13C NMR and IR spectroscopy that the interaction of pharmacophore-containing pectins with d-metal ions (Cu2+, Co2+, Mn2+) occurs via the carbonyl and hydroxyl groups of the modified polymer matrices. The viscosity and thermal properties of the metal complexes have been determined.  相似文献   

16.
以1-乙烯基咪唑(1-VIm)和甲基丙烯酸甲酯(MMA)为共聚单体,通过溶液聚合反应合成出4种不同比例的无规共聚物.通过锐孔-凝固浴法,将所得共聚物的四氢呋喃溶液滴入到Cu Cl2水溶液中形成Cu2+-P(VIm/MMA)微胶囊.该微胶囊壁材上的组成部分与离子、分子反应,通过壁材的溶解、分解、解聚而使壁材崩溃或者通过溶胀而改变囊壁的渗透性.通过傅里叶红外光谱、元素分析仪、光学显微镜和扫描电子显微镜对4种不同单体比例的共聚物进行了表征,结果表明当PVM-30浓度为20 g/L时制备的微胶囊成球效果最好,其粒径大小约为1 mm,壁厚为350μm.通过核磁共振氢谱(1H-NMR)分析了PVM-30的结构,利用凝胶渗透色谱(GPC)测定了共聚物的分子量,PVM-30平均分子量在16.0×103左右.利用傅里叶红外光谱和热重分析仪对微胶囊的成分进行了研究,结果表明微胶囊壁材是由PVM与Cu2+配位得到的配位聚合物组成.探索了微胶囊在水溶液中对NO3-、SO42-和CO32-3种离子的响应特性,发现只有浸泡在CO32-离子溶液中的微胶囊的壁材出现了裂痕,最终生成了更稳定的蓝色配位离子溶液,实现了对微胶囊的化学触发.  相似文献   

17.
18.
Photoconductivity has been measured in well-dried poly(vinyl alcohol) (PVAl) films containing Cu2+ complexes prepared by treatment with Cu(NO3)2, CuSO4, CuCl2, and CuBr2. When the ratio [Cu2+]/[MU] ([MU] denoting the concentration of PVAl monomer residues) is greater than 0.015, illumination at the charge-transfer (UV) band produces a strong photocurrent in PVAl-CuCl2 and PVAl-CuBr2, but not in PVAl-Cu(NO3)2 or PVAl-CuSO4. Optical absorption spectra suggest that two halide ions enter the first coordination sphere in the cis configuration. The temperature dependence of ESR indicates the existence of antiferromagnetic superexchange interaction via intervening halide ions. Hence, there exists a network structure of the PVAl-CuCl2 or PVAl-CuBr2 complex. The dependence of the photocurrent on the polarity of the illuminated electrode shows that the majority of carriers are holes. Holes in the network structure produced by charge transfer from halogen to Cu2+ ions are concluded to be responsible for the photoconduction.  相似文献   

19.
Cu(II)在对甲苯磺酸铜+DMSO中的电还原   总被引:19,自引:0,他引:19  
制备了对甲苯磺酸铜并首次用于电化学实验.差示扫描量热和热重曲线测定表明,对甲苯磺酸铜结晶容易脱除全部结晶水,无水盐在空气中不潮解.用循环伏安曲线、计时电流曲线和恒电流电解后的电位-时间曲线研究Cu(Ⅱ)在二甲基亚砜(DMSO)溶液中的电还原.结果表明, Cu(II)电还原为Cu的反应分两步进行,其中第一步是可逆过程.测定了Cu(II)在DMSO溶液中的扩散系数.  相似文献   

20.
A new macrocyclic ligand, 1,4,8,11-tetraazacyclotetradecane-1,8-bis(methylphosphonic acid) (refered to as dipon) exhibits high thermodynamic and kinetic selectivity for Cu2+ compared to other transition metal ions. The initial-rate method (=310nm, pH=3.75, cL4.6×10–3molL–1) was chosen as an optimal experimental approach in order to achieve maximum sensitivity of determination. The dynamic range of the method is (5–200)×10–6molL–1, and the detection limit is 2.5×10–6molL–1. A standard addition procedure was applied to the kinetic determination of Cu2+ to eliminate the effect of interfering ions (e.g. Zn2+, Ca2+, Mg2+, Cd2+, Pb2+, Mn2+, Co2+, Ni2+, HCO3, Cl, SO42–, etc.). The method was tested on artificial and real samples (alloys, pure and spiked mineral water) and gave satisfactory results which are in agreement with the values for some certified materials. The advantage of the proposed method is rapidity, simplicity and robustness in the presence of other metal ions.  相似文献   

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