Metal complexes stabilization

Acetic acid, ethylenebis(oxyethyleneimino)tetra-metal complexes stability, 2, 786... 

Metal-complex stability is also related to the basic strength of the ligand entity. For a series of 1 2 complexes of the bidentate naphthylazophenol ligand (5.64) with copper(II) ion, the acidic dissociation constants (pKa) are linearly related to the stability constants (log K1 2), the more acidic groups forming the less stable complexes. Thus where X = N02 in structure 5.64 then pKa = 8.1 and log K1 2 = 17.2, and where X = OCH3 then pKa = 8.5... 

Scheme 8 Metal complexes stabilized by CAAC ligands...

Noble metals, complex stability of, 3 267-268 Nocardia opaca hydrogenase, 32 315, 321-322... 

In a series of tetrabenzoazaporphyrins there are tendencies coupled to the increase in the number of meso nitrogens, such as the decrease in stability, the increase in sublimability, the decrease in basicity, the increase in oxidizability, the red shift of main absorption bands and the increase in metal complex stability.195... 

Hydrosulfido complexes, 517 bonding, 519 reactivity, 519 structures, 519 synthesis, 518 types, 518 Hydroxamates metal complexes, 505-508 Hydroxamic acid, N-methyl-metal complexes, 507 Hydroxamic acid, phenyl-metal complexes stability, 506 Hydroxamic acids... 

Brown, S.D. and Kowalski, B.R., 1979. Pseudopolarographic determination of metal complex stability constants in dilute solution by rapid scan ASV. Anal. Chem., 51 2133-2139. 

In the case of germanium and tin, reactions such as (162) lead to the production of GeMe - or SnMejj-metal complexes, stabilized by electron donation from the Lewis base, tetrahydrofuran (315). 

Stability constants - this database of metal-complex stability constants available on disk contains 25 000 pieces of data. 

Both steric and electronic effects contribute to the magnitude of the formation constant. The effect of sterics are often assessed with the use of molecular mechanics calculations (Chapter 6) and electronic effects, by studying linear free energy relationships— the relationship between free energies and rates of complex formation. HSAB and CFT (or LFT) are used regularly to predict and rationalize metal complex stability. 

In this experiment, the electrochemistry of both [Co(en)3]3+/2+ and [Co(ox)3]3+/2+ will be investigated using cyclic voltammetry, and the standard reduction potential (E°, V) for the [Co(en)3]3+/2+ couple will be measured. For metal complex stability reasons discussed below, it is not possible to use this technique to obtain reduction potentials for the mixed ligand cobalt systems an exercise at the end of this experiment helps to estimate these. The E° values obtained will be important for experiment 5.6, in which outer-sphere electron transfer rate constants between [Co(en)3)]2+ and [Co(en)2)(ox)]+ will be mathematically modeled using Marcus theory. 

Propargylic radicals are generated on reduction of metal-complex-stabilized Nicholas cations with Zn. This principle, which has been found very recently [21], can be used for ring-closure reactions via intramolecular radical recombination [Eq. (12)]. 

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