Oxidation of benzaldehyde by dioxygen. The thermal reaction

1982 ◽  
Vol 47 (2) ◽  
pp. 392-402 ◽  
Author(s):  
Pavel Lederer ◽  
Stanislav Luňák ◽  
Eva Mácová ◽  
Josef Vepřek-Šiška
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Transition Metal Ions ◽  
Thermal Reaction ◽  
Oxidation States ◽  
Reaction Step ◽  
Free Radical Formation ◽  
Trace Concentrations ◽  
Lower Oxidation

The oxidation of benzaldehyde is catalyzed by transition metal ions even when these are present in trace concentrations. In complete absence of the ions, the reaction between benzaldehyde and dioxygen would not take place. A study has been made of the oxidation of benzaldehyde in benzene catalyzed by transition metal complexes. The catalytic activity of transition metals is higher when they assume their lower oxidation states. When the reaction is catalyzed by iron(III) bis(2,4-pentanedionato)-complex, the first reaction step is the reduction of Fe(III) to Fe(II), the latter being the catalyst of the thermal reaction. The mechanism proposed for the catalyzed reaction does not involve free radical formation.

Synthesis, Characterization and in vitro Biological Evaluation of a New Schiff Base Derived from Drug and its Complexes with Transition Metal Ions

2018 ◽  
Vol 69 (7) ◽  
pp. 1678-1681
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Metal Ions ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Free Ligand ◽  
Transition Metal Ions ◽  
Biological Evaluation ◽  
Pyridoxal Hydrochloride

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.

The effect of partial exchange of sulphonated macroporous styrene-divinylbenzene copolymers for different ions on their catalytic activity

1981 ◽  
Vol 46 (10) ◽  
pp. 2354-2363 ◽  
Author(s):  
Svatomír Kmošták ◽  
Karel Setínek
Keyword(s):  
Catalytic Activity ◽  
Transition Metal ◽  
Metal Ions ◽  
Gas Phase ◽  
Transition Metal Ions ◽  
Exchange Capacity ◽  
Total Exchange Capacity ◽  
Styrene Divinylbenzene ◽  
Na Ions ◽  
Type Of Transition

The catalytic activity of sulphonated macroporous styrene-divinylbenzene copolymers, the exchange capacity of which was neutralized from 30, 50 and 80% by Fe(III) ions and from 30% by Na ions and that of Wofatit Y-37 ion exchanger neutralized from 10% of its total exchange capacity by several transition metal ions and by sodium has been studied in isomerisation of cyclohexene and dehydration of 1-propanol in the gas phase at 130 °C. It was demonstrated that in both reactions transition metal ions exhibit additional effect to the expected neutralization of the polymer acid groups. In the case of cyclohexene isomerization, this effect depends on the degree of crosslinking of polymer mass of the catalyst. Such dependence has not been, however, observed in dehydration of 1-propanol. The type of transition metal ions did not exhibit any significant effect on the catalytic activity of the polymer catalysts studied.

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