Preparation of metal chelate

For Cd and Hg, Cd(FDEDTC)2 and Hg(FDEDTC)2 chelates were prepared with Li(FDEDTC) as the chelating reagent, using the procedure described above. 

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The method of ligand exchange has been used for preparation of metal chelates, containing N,S- 697 (3.110) [283] and N,Te-donor atoms 698 (3.111) in the coordination unit ... 

The preparation of metal chelates for separations by gas chromatography has been studied for many years by now. The principal limit to the success of this approach has been the paucity of suitable reagents which can confer the necessary volatility and thermal stability and an adequate shielding of the metal atom from unwanted column interactions. 

The preparation of metal chelate polymers from bis(o-hydroxyazo) ligands has been reported. Bis[(o-hydroxyphenyl)azo]- [49] (18-20) and bis(3-hydroxy-4-azopyrazolone) [50] (19,20) compounds are polymerizable. With both classes of ligands, black, intractable products were obtained on reaction with metal salts. Only Cu(II) polymers have been investigated. Dimethylformamide, dioxane, and dioxane-ethanol mixtures were used as solvents. The products were not characterized because of their insolubility. 

A number of metal chelates containing transition metals in their higher oxidation states are known to decompose by one electron transfer process to generate free radical species, which may initiate graft copolymerization reactions. Different transition metals, such as Zn, Fe, V, Co, Cr, Al, etc., have been used in the preparation of metal acetyl acetonates and other diketonates. Several studies demonstrated earlier that metal acetyl acetonates can be used as initiators for vinyl polymeriza-... 

The preparation of new chelating agents containing vicinal thiols, such as the EDTA-bis-(0-2,3-dimercaptopropyl)ester (43), could lead to new metal-binding ligands which... 

A change of salt anions allows us to carry out controlled syntheses of definite types of coordination compounds. Thus, metal halides are widely used to prepare molecular (Sec. 3.1.1.1) and ti-complexes (Sec. 3.1.1.3). Metal acetates are mostly applied in the syntheses of metal chelates and, especially, inner-complex compounds (Sec. 3.1.1.2). Di- and polynuclear structures are formed under use of the anions mentioned above, which, in some cases, determine (see Sec. 3.1.1.4) a type and donor centers of bridge fragments. At the same time, the mentioned approach to choice of salts of metal complex-formers has many exceptions, although it is useful. 

The synthesis on a metal matrix is mainly applied to prepare chelate complexes. The majority of template synthesis reactions were known long ago, allowing their use for the isolation of hundreds of metal-chelate structures. However, the interest in... 

As a first step toward this purpose, we have studied the chelation effect of tetrapeptides of sequences Cys-X-Y-Cys, by preparation of metal complexes of mainly the first transition series. The hydrophobic effect of the peptides was also studied by utilizing the side chain bulkiness of the amino acid residues interposed between the two cysteine residues. A special effect of aromatic side chains of tyrosine, phenylalanine, and tryptophan has also been examined in order to assess their ability to ease electron transfer to and from the nearby iron core. 

Many synthetic dyes such as porphyrins, acridine, thlonlne and flavin dyes have been used in photosensltlzatlon of electron transfer reactions. In the past few years several promising organometalllc compounds have been prepared as substitutes for the natural labile chlorophyll. These organometalllcs Include a variety of metals, chelated to bipyridine or porphyrin ligands ( ). The photophysical properties of these sensitizers and their potential use in artificial photosynthetic devices have been extensively reviewed ( 7, ). In particular, sensitizers such as... 

This procedure, a variant of method 3, is also potentially a very useful method. An advantage is that the pH of the reaction mixture is controlled by the amount of amine present. In theory, the use of this method would permit the preparation of metal derivatives of a wide variety of /8-keto imines and obviate the need for preparation and isolation of the individual ligands. In practice, it appears that of the possible compounds the most stable metal chelate compound is formed. This may not always be the desired compound. Thus, even in the presence of copper-(II) ion, the condensation of 4-imino-2-pentanone and trimethylenediamine was not successful, the product isolated being bis(4-imino-2-pentanonato)copper(II). ... 

Sapieszko, R. S. and Matijevic, E. (1980) Preparation of well defined colloidal particles by thermal decomposition of metal chelates. I Iron oxides. J. Coll. Interface Sci. 74 405-422. 

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