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Edta and Related Ligands

de Filippo, F. Devillanova, and C. Preti, Inorg. Chim. Acta, 1969, 3, 341. [Pg.190]

In the partial dissociation mechanism, association of the incoming ligand with the metal begins before dissociation of the outgoing ligand is complete, giving an intermediate or intermediates in which the cation is bonded to both ligand molecules e.g. [Pg.191]

A variant of this mechanism is sometimes encountered in which the formation of the mixed ligand complex is preceded by a kinetically distinguishable pre-equilibrium partial dissociation of the starting complex e.g. [Pg.191]

The denticity of the ligands in the intermediates of equations (2) and (3) is difficult to determine, though attempts have been made in certain systems, for example in nitriloacetate exchange. Any of the paths described above may be acid catalysed, as is illustrated in, for example, edta exchange studies.  [Pg.191]

The effect of added ligands on this type of reaction has been studied for the replacement of edta complexed to nickel(n) by Eriochrome Black T. [Pg.191]


In many cases, the inflexions present in the plots of AH and AS vs. atomic number compensate, leading to much smoother curves for corresponding plots of AG or K. Examples of this type of behaviour are shown in reference 405, where values of AG, AH and AS for lanthanide complexes with edta and related ligands are plotted. Extensive lists of association constants for edta-type and other carboxylate ligands have been given.414,415... [Pg.1088]

The most important ferrous developers, however, are the complexes with ethylenediaminetetraacetic acid (EDTA) and related ligands, such as diethylenetriaminepentaacetic add (DTPA), nitrilotriacetic add (NT A) and JV-hydroxyethylethylenediaminetriacetic add (HETA). Complexes... [Pg.98]

Ethylenediamine tetraacetic acid (EDTA) was introduced originally as a water-softener and as a textile dyeing assistant because of its ability to form very stable, water soluble complexes with many metal ions, including calcium and magnesium. The equilibria involved in chelation of metal ions by EDTA and related ligands have been exhaustively studied, notably by G. Schwarzenbach and his colleagues, and provide the basis for complexometric methods of chemical analysis. EDTA and its metal complexes have also become probably the most familiar examples of agents used in chelation therapy. [Pg.199]

Many dithiocarbamate complexes of zinc, silver, cadmium or mercury improve emulsion stability, including bis(dibenzyldithiocarbamato)-zinc(II) or -cadmium(II) and silver(I) diethyldi-thiocarbamate. Cadmium salts, mixed with citric acid or tartaric acid and added to the emulsion, are reported to be effective. Mercury(II) complexes of ethylenediaminetetraacetic acid (EDTA) and related ligands and of solubilized thiols such as (4) can be used. Other coordination compounds reported include EDTA and related ligand complexes of Co and Mn, mixtures of Co salts with penicillamine (5) and macrocyclic complexes of Ag such as (6). The latter compounds may be used in diffusion transfer systems in which transferred maximum densities are stabilized. [Pg.98]

The interaction of aspartic acid and other ligands with complexes of Tb " with edta and related ligands has also been studied and association constants determined. The complex formation between Tb " or Eu " and (r)-( — )-l,2-propanediaminetetraacetic add or (r,r)-trons-1,2-cyclohexanediaminetetraacetic acid has been similarly investigated. The pH dependence of the circularly polarized and total luminescence shows a drastic configurational change of the chelate system at pH 10.5-11, corresponding, it is believed, to formation of hydroxide complexes. Tlie technique of magnetic-field-induced circularly polarized emission has been introduced for lanthanide ions the mechanisms of lanthanide transition intensities are also discussed in the paper. [Pg.2947]

Mechanisms of metal exchange for complexes of edta and related ligands... [Pg.193]

Some years ago it was claimed that the [Fe(fz)3] anion reacted with oxalate by a bimolecular mechanism. Nucleophilic attack of oxalate at metal or ligand here seemed equally unlikely, and a reinvestigation of this reaction, with a parallel study of reactions of this complex with edta and related ligands, indicates a dissociative mechanism, with ligand competition causing the observed kinetic pattern. ... [Pg.233]

Several papers deal with ligand replacement (by edta and related ligands) in copper(ii) complexes. The role and structure of mixed-ligand intermediates in the displacement of trigly or glycinamide by edta or cydta have been discussed. [Pg.233]

Co(LLLL)(L)X] + and [Co(LLLLL)X] + Complexes. Included in this section are studies in which the non-leaving group is an open-chain or cyclic quadridentate (LLLL) or quinquedentate (LLLLL) ligand. Excluded are the complexes of edta and related ligands discussed earlier and the dioximato-complexes covered in the next section. [Pg.178]


See other pages where Edta and Related Ligands is mentioned: [Pg.215]    [Pg.565]    [Pg.683]    [Pg.1059]    [Pg.1087]    [Pg.1108]    [Pg.140]    [Pg.14]    [Pg.98]    [Pg.100]    [Pg.42]    [Pg.42]    [Pg.95]    [Pg.14]    [Pg.100]    [Pg.240]    [Pg.2898]    [Pg.2926]    [Pg.6159]    [Pg.6245]    [Pg.190]   


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