Activating Effect of Ligands for Metal Ion Catalysis and Structure of Metal Complexes

络合剂（多磷酸盐、氨基多羧酸盐等）的作用本文用电位法研究了钒（V）、铜（II）与铁（II）氧化还原反应的影响。铜（II）与铁（II）的氧化还原反应在二磷酸盐和2，9-二甲基-1，10-菲咯啉（新亚铜灵）的存在下有利地进行以形成铜（I）-新亚铜灵络合物。用EXAFS方法测定了铜（Ⅱ）与吡啶、2，2 ′-联吡啶、1，10-菲咯啉和氨基羧酸盐配合物的结构。单-、双-、三-和四（吡啶）铜（II）络合物具有轴向伸长的八面体结构。2，2 ′-联吡啶与1，10-菲咯啉的单配合物和三配合物的结构也是畸变八面体。在这些配合物中，赤道Cu-O和Cu-N键距随温度的升高而略有延长， 关于我们 增加平均配体数。轴向的Cu-O和Cu-N的距离几乎是相同的，除了四（吡啶）铜（II）的配合物，其中的Cu-O键的距离是明显延长可能是由于空间排斥。双（2，2 '-联吡啶）铜（II）配合物具有五配位三角双锥结构。配合物中的Cu-O键长远大于六水合铜离子和单配合物中的Cu-O键长。单-和双（氨基羧酸根）铜（II）配合物具有轴向伸长的八面体结构。赤道和轴向的Cu-N和Cu-O键长几乎保持不变的形成后的单和双的络合物的氨基羧酸根离子independent.Kinetics的锌（II），镉（II），铅（II）-卟啉与乙二胺四乙酸（EDTA）的配体取代反应的动力学和机理进行了研究。锌（II）卟啉与EDTA的置换反应机理与镉（II）或铅（II）卟啉的置换反应机理有很大不同。锌（II）、镉（II）和铅（II）卟啉的反应性的巨大差异已被应用于在大量镉（II）或铅（II）存在下测定痕量锌（II）。研究还表明，在卟啉与核苷酸形成分子复合物的过程中，卟啉与核苷酸之间的疏水相互作用比静电相互作用更重要。少

The effect of complexing agents (polyphosphates, aminopolycarboxylates, etc.) on the redox reactions of vanadium (V) or copper (II) wiht iron (II) has been studied by means of potentiometry. The redox reaction of copper (II) with iron (II) favorably proceeds by the presence of diphosphate and 2, 9-dimethyl-1, 10-phenanthlorine (neocuproine) to form the copper (I) -neocuproine complex. This reaction has been applied to the photometric determination of iron (II) with a flow injection analysis.Structure of copper (II) complexes with pyridine, 2, 2'-bipyridine, 1, 10-phenanthlorine, and aminocarboxylates in aqueous solution has been determined by the EXAFS method. The mono-, bis-, tris-, and tetrakis (pyridine) copper (II) complexes have an axially elongated octahedral structure. The structure othe mono- and tris-complexes of 2, 2'-bipyridine and 1, 10-phenanthlorine is also distorted octahedral. In these complexes the equatorial Cu-O and Cu-N bond distances are slightly lengthened with in … More creasing the average ligand numbers. The axial Cu-O and Cu-N distances are practically the same except for the tetrakis (pyridine) copper (II) complex, in which the Cu-O bond distance is appreciably lengthened probably due to the steric repulsion. The bis (2, 2'-bipyridine) copper (II) complex has a five-coordinate trigonal bipyramidal structure. The Cu-O bond distance within the complex is much longer than that within the hexaaquacopper (II) ion and the mono-complexes. The mono- and bis (aminocarboxylato) copper (II) complexes have an axially elongated octahedral structure. Both equatorial and axial Cu-N and Cu-O bond distances virtually remain unchanged upon the formation of the mono-and bis-complexes independent of aminocarboxylate ions employed.Kinetics and mechanism of the ligand-substitution reaction of zine (II), cadmium (II), and lead (II) -porphyrins with ethylenediaminetetraacetic acid (EDTA) has been studied. The reaction mechanism on the replacement of zinc (II) porphyrin with EDTA is largely different from that of cadmium (II) or lead (II) -porphyrins. The large differences in the reactivities of zinc (II), cadmium (II), and lead (II) porphyrins have been applied to the determination of trace zinc (II) in the presence of a large amount of cadmium (II) or lead (II). It is also shown that, in the molecular complex formation oo porphyrins with nucleotides, the hydrophobic interaction between porphyrin and nucleotides is more important than the electrostatic interaction. Less