Cobalt Schiff-base complex

An X-ray photoelectron spectroscopic study (132) of some cobalt(II) Schiff base complexes and their dioxygen adducts finds that the cobalt core electron binding energies in... 

In this section, we present material dealing with the direct oxidation and reduction of a variety of organocobalt species, including complexes with more than one cobalt center, electrodes functionalized with cobalt complexes, cobalt-containing SchifF-base complexes, cobalt porphyrins and corroles, and macrocyclic tetraamines. 

Cobalt(II)-Schiff-base complexes with a nitrogenous base are also well known to bind molecular oxygen in an organic solvent at room temperature. 

A more complete article (58b) further details the properties of faujasite EMT-entrapped cobalt(II)-Schiff base complexes as compared to the same complexes entrapped in zeolite Y. The Schiff bases used to... 

Although there has been a great deal of research concerning how plahnum(II) complexes bind to biological molecules and the hkely mechanism of antitumor activity of these platinum-containing species, far less attention has been paid to the properties of other metal complexes in this arena. Recent attention has fallen on cobalt(II)-Schiff base complexes, as several have been discovered to have promise as antiviral agents. A review of recent work has appeared elsewhere [64], so the topic will not be covered here however, in addition to focusing on recent developments, emphasis is placed on the introduction of the new head unit, 3,6-diformylpyridazine (13), into Schiff-base macrocyclic electrochemistry. 

More recently, Drago and coworkers [23] have shown that the alcohol solvent takes part in the reaction by reducing the Rh(III) to Rh(I). This is followed by reaction of Rh(I) with O2 and a proton to give a Rh(III) hydroperoxide complex which oxidizes the olefin. Similarly, Drago [24] and Nishinaga [25] found that cobalt(II) Schiff base complexes catalyze the co-oxidation of olefins and primary alcohols (reaction 13). 

A full account of the electron-transfer reactions of cobalt(ii) and cobalt(iii) Schiff-base complexes, including some fluoroalkyl-cobalt complexes, has now appeared (c/ Vol. 2, p. 317). ... 

Fugii et al. [26] reported one of the earliest examples of selective recognition using metal coordinated molecular imprinting. They utilized a polymerizable cobalt (III) Schiff base complex as the recognition element in an MIP designed for the selective... 

Cesarotti, M. Gullotti, A. Pasini, A. Ugo, R. Optically active complexes of Schiff bases. Part 5. An investigation of some solvent and conformational effects on the equilibriums between cobalt(ll) Schiff-base complexes and dioxygen. J. Chem. Soc. Dalton Trans. 1977, 8, 757-763. 

Losada, J., I. Del Peso, L. Beyer, J. Hartung, V. Fernandez, and M. Mdius (1995). Electrocatalytic reduction of O2 and CO2 with electropolymerised films of polypyrrole cobalt(II)Schiff-base complexes. J. Electroanal. Chem. 398, 89-93. 

Electron spin resonance spectra provide direct information about paramagnetic metal complexes. Much experimental work has been done on cobalt(II) Schiff-base complexes and their 0 - adducts. Some related... 

Five-coordinate cobalt(II) Schiff base complexes of the Co(salen)B... 

In the presence of primary alcohols the cobalt II) Schiff-base complex Co NMe-salpr) has been found to catalyze the oxidation of both internal and terminal olefins by 0 to the corresponding 2-ketone and... 

The series of sterically crowded cobalt(II) Schiff base complexes Co(Busalen) have been investigated as catalysts for the oxidative cleavage of 3-methylindole [213,214]. The major product is... 

The oxygenation of 4-substituted phenylacetylenes (70) in alcohols is catalyzed by Co(salen) [272] and other cobalt(II) Schiff base complexes [273]. The reaction leads to selective incorporation of oxygen, affording the corresponding acetophenones 71, together with mandelic (72) and phenylglyoxylic (73) acid esters. 

The cobalt(II) Schiff-base complexes Co(salen) and Co(salpr), as well as their 5-coordinate derivatives LCo(salen) and LCo(salpr) catalyze the oxidation of substituted phenols by dioxygen. This propensity is due to the formation of dioxygen complexes upon contact with 0, which is usually reversible, especially in nonprotic solvents. 

The oxidation of hindered phenols and naphthols catalyzed by Mn(TPP)Cl, cobalt(II) Schiff-base and dimethylglyoximatocobalt(II) (cobaloxime) complexes has been studied by Gaudemer et al. [49]. The following catalysts and substrates were used ... 

The cobalt(II) Schiff base catalyst forms a superoxocobalt(III) complex which converts the phenol into an aryloxy radical, itself being transformed into free or coordinated HO radical ... 

Aromatic amines show a variety of oxidation patterns. Secondary aromatic amines are dehydrogenated to imines if cobalt(II) Schiff-base complexes are used as catalysts. o-Phenylenediamine is dehydrogenated to the diimine which yields diaminophenazine with Co(II) as catalyst. Benzimidazole derivatives are obtained with Cu(II). 

The complex of cobalt with Schiff base was dissolved in 24 mmol of APTES, then 48 mmol of TEOS were added to this system. The obtained solution was placed on an ice-bath and 0.26 mol of H2O was added while mixing. After a few minutes, the mixt ire was solidified. It was crushed, allowed to stand at room temperature for two hours, and dried for six hours at 100°C. The solid was washed with water (600ml) and dried at 100°C once more. The obtained catalyst was a light-brown powder. The product yield was 6 g. For the preparation of incorporated Cosalophen complex with Cco=10.8.10 mol/g, 10ml of DMFA was added to the systems. 

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