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本文用示差脉冲极谱技术研究Pb(Ⅱ) 络合剂(β N 三丙酸)体系。依据实验得到的极谱峰电位的移动随溶液pH值的变化关系曲线,建立合适的金属络合物体系模型。用计算机分析程序,通过求解体系的质量平衡方程及拟合实验络合物形成曲线,优化得到金属络合物的稳定常数。计算机分析结果表明,在所研究的pH值范围内,溶液中存在四种金属络合物:PbH2L+、PbHL、PbL-、PbL(OH)2-,其稳定常数(logβ)分别为:16.23±0.04、12.42±0.01、4.11±0.05、9.43±0.02。 相似文献
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在5×10-5mol·L-1Bi(Ⅲ)溶液中,增加络合剂邻吡啶甲酸的浓度,用示差脉冲极谱法研究铋 邻吡啶甲酸体系。通过计算机分析程序求解体系的质量平衡方程及拟合试验络合物形成曲线,优化得到铋和邻吡啶甲酸形成的络合物BiL2+和BiL+2的稳定常数,分别为7.51±0.03和13.92±0.04。 相似文献
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金属离子Bi(Ⅲ)络合物体系的极谱法研究 总被引:1,自引:0,他引:1
The B(i Ⅲ)-Ligand(pyridine-2-carboxylic acid)system was studied by the differential pulse polarography(DPP)at the fixed total-ligand to total-metal concentration ratio[LT]:[MT]and varied pH. An appropriate model for the metal complex system is designed according to polarographic peak parameters,that is,the observed shift in the peak potential and the change in the peak current with pH changes in the sample solution. The polarographic experimental complex formation curve(ECFC)and theoretical complex formation curve(TCFC)were used for checking the designed metal complex model as well as optimizing stability constants. The ECFC,in which experimental parameters(a shift in a peak potential and a variation in a peak current)are included,appears to be a characteristic function for a particular metal-ligand system. The TCFC is a theoretical curve calculated from massbalance equations for the designed metal-ligand model. Using the computer analytical program,stability constants of metal complexes and species distribution diagrams are obtained by solving the mass-balance equations written for the metal complex system and fitting the complex formation curve. Five bismuth complexes MHL,ML,ML2,ML3,ML3 ( OH),and their stability constants as logβ 7.52±0.15,7.48±0.06,13.94±0.02,18.12±0.03 and 26.78±0.03,respectively,are finally reported while the TCFC fits best the ECFC. 相似文献
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本文介绍和评价了测定络合物稳定常数的离子交换平衡法,特别注重了腐殖酸络合物稳定常数的测定。 相似文献
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本文利用导数光谱法消除体系中共存有关物种干扰,直接测定游离配体浓度。基于此仿照对应溶液法的图解法,我们拟订两个测定络合物稳定常数的新方法。方法简便可靠,试用于La-BPR体系获得了令人满意结果。 相似文献
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本文利用溶液的稀释度与其吸光度的关系,导出一个适用于不稳定络合物稳定常数的测定方法。当络合物的摩尔吸光系数(ε)不能直接测定时,本法可直接求算它的稳定常数及摩尔吸光系数。本文还讨论了方法误差与络合物离解度以及溶液稀释度的关系。 相似文献
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用般谱法研究了Cd(Ⅱ)-2,2′-联吡啶(bipy)、Cd(Ⅱ)-甘氨酸(Gly)二元体系及cd(Ⅱ)-bipy-Gly三元体系的配合物的形成条件,用极谱法测定了不同浓庹配体的E1/2(a)、E1/2(c)、ΔE1/2、(id)s和(id)c值,利用Lrden函数作图,外推求得各级稳定常数。 相似文献
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联合处理电位法和极谱法得到的实验数据确定金属配合物稳定常数(英) 总被引:1,自引:0,他引:1
The cadmium(Ⅱ)-glycinamide system was modeled and its stability constants were calculated by a unified mathematical treatment for experimental data obtained from ion selective electrode (ISE) and differential pulse polarography (DPP). It has been shown that very much the same experimental complex formation curve (ECFC) and theoretical complex formation curve (TCFC) could be given from both experimental techniques for the same experimental conditions, such as the same total ligand c(LT) and metal ion c(MT) concentrations. The combination of the two techniques is of many advantages as ISE can be performed at low a c(LT)∶c(MT) ratio and significantly higher c(MT), whereas DPP could be used well at larger the c(LT)∶c(MT) ratio and very low c(MT). This makes it possible to study a metal-ligand system in much broader range of experimental conditions that, in turn, provides us more data and information about the metal-ligand system of interest. Application of the unified mathematical treatment to the cadmium-glycinamide system in this paper, three new complexes MHL, ML3 and ML3(OH) as well as two complexes ML and ML2, reported in literatures, could be modeled and all their stability constants have been refined. 相似文献
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The cadmium(Ⅱ)-glycine system was studied by the two experimental techniques, ion sensitive electrode (ISE) and differential pulse polarography (DPP), and the experimental data obtained were used by a unified mathematical treatment to calculate the complex stability constants. The combination of the two techniques is of many advantages as ISE can be performed at low LT:MT ratios and significantly higher MT, whereas DPP could be used well at large LT:MT ratios and much smaller MT. This makes it possible to study a metal-ligand system in a relatively broader range of experimental conditions that, in turn, provides more information about the metakligand system of interest. Applying the unified mathematical treatment to the cadmium-glycine system, two new complexes MHL and ML2(OH) as well as three complexes ML, ML2 and ML3, reported in literatures, could be modeled and all their stability constants have been refined. 相似文献
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柱上衍生反相色谱法测定金属配合物的稳定常数 总被引:7,自引:0,他引:7
提出一种计算金属配合物稳定常数的新方法。应用住上衍生反相高效液相色谱法,以二乙基二硫代氨基甲酸钠为配体,测定金属配合物的保留时间,用以推导金属配合物的稳定常数。 相似文献
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1 INTRODUCTION The synthesis and study of transition metal com- pounds incorporating organic free radicals directly bound to their coordination sphere are a major re- search aim in the field of molecular magnetism[1]. Exceptional stability, ease of chemical modification and versatility in their coordination properties have made nitroxide free radicals one of the most attrac- tive spin carriers for the design of molecular magne- tic materials[2, 3]. The structures and magnetic prope- rties … 相似文献
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Katsumasa Misawa Yoshihiro Saito Kaname Hashizaki Hiroyuki Taguchi Naotake Ogawa Haruhisa Ueda 《Journal of inclusion phenomena and macrocyclic chemistry》2005,53(3):237-240
Modified static head-space gas chromatography method (M-SHSGC method) was used to determine the stability constants of benzene and alkylbenzenes with 2-hydroxypropyl-β-cyclodextrin inclusion complexes. The 1:1 stability constants were in agreement with those obtained by conventional SHSGC method. The M-SHSGC method precludes the necessity of the calibration curve by the use of Henry’s law constant of guest. Consequently, it is more advantageous than conventional SHSGC method because the time required to determine the stability constant is markedly reduced. 相似文献