Belousov-Zhabotinskii reaction with ethyl ester of 3-oxobutanoic acid

1983 ◽  
Vol 48 (11) ◽  
pp. 3229-3237 ◽  
Author(s):  
Ľudovít Treindl ◽  
Arpád Nagy
Keyword(s):  
Carbon Dioxide ◽  
Ethyl Ester ◽  
Platinum Electrode ◽  
Reaction System ◽  
Bromo Derivative ◽  
Oscillation Reaction ◽  
Oxobutanoic Acid ◽  
Belousov Zhabotinskii Reaction

The modified Belousov-Zhabotinskii oscillation reaction with ethyl ester of 3-oxobutanoic acid is remarkable in that it does not yield carbon dioxide and the reaction system is closed and homogeneous until an emulsion of a bromo derivative of the substrate appears. As long as the system is homogeneous, it oscillates even in the motionless state and its oscillation behaviour in the absence of oxygen is independent of the intensity of stirring. The results obtained by polarography with a rotating platinum electrode are in agreement with those obtained by spectrophotometry.

Kinetics of oxidation of α-ketoglutaric acid with Ce(IV) ions in relation to Belousov-Zhabotinskii reaction

1982 ◽  
Vol 47 (11) ◽  
pp. 2831-2837 ◽  
Author(s):  
Ľudovít Treindl ◽  
Vasil Dorovský
Keyword(s):  
Redox Reaction ◽  
Platinum Electrode ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Redox Catalyst ◽  
Oscillation Reaction ◽  
Belousov Zhabotinskii Reaction ◽  
Kinetics Of

Oxidation of α-ketoglutaric acid with Ce(IV) ions in a solution of sulphuric acid is a reaction of the first order with respect to both Ce(IV) ions and substrate, is acid catalysed, and its rate is proportional to the reciprocal square of the equilibrium HSO4- concentration. From the temperature dependence of the rate constant in 1.5M-H2SO4, the activation parameters were determined as ΔH##f = 57 kJ/mol and ΔS##f = -45 J mol-1 K-1. The redox reaction proper consists apparently of two steps: in the first one, the enol form of α-ketoglutaric acid reacts with Ce(IV) ions with the formation of the corresponding radical; in the second one, the latter is oxidized further with Ce(IV) to give malonic and succinic acids. Conditions are indicated under which α-ketoglutaric acid serves as substrate for the Belousov-Zhabotinskii oscillation reaction in the presence of Ce(IV)-Ce(III) redox catalyst. Oscillations of Ce(IV) and Br2 concentrations, shifted in phase, can be recorded polarographically with a rotating platinum electrode.

Oscillation system of Belousov-Zhabotinskii type in presence of Cl- ions

1986 ◽  
Vol 51 (12) ◽  
pp. 2693-2701 ◽  
Author(s):  
Marta Mrákavová ◽  
Ľudovít Treindl
Keyword(s):  
Reaction Mechanism ◽  
Ethyl Ester ◽  
Reaction System ◽  
Oscillation System ◽  
Low Concentration ◽  
Redox Catalyst ◽  
Probable Reaction Mechanism ◽  
Oxobutanoic Acid ◽  
Probable Reaction

A modified Belousov-Zhabotinskii oscillation system involving ethyl ester of 3-oxobutanoic acid and Fe(phen)32+ - Fe(phen)33+ as redox catalyst is remarkable in that it shows an oxygen-induced excitability. The oscillating state, involving 4-5 oscillations in the absorbancy of Fe(phen)32+ ions, comes soon to its end but can be restored by shaking the reaction system, thus incresing the transport of oxygen from the air. This phenomenon is not influenced by Cl- ions in a low concentration, but if this is equal to 10-3 mol dm-3 or higher, no oscillations are observed, the increase of the concentration of Fe(phen)32+ ions is autocatalytic in character and can be reproduced several times by shaking or stirring the solution. These phenomena are discussed in terms of a probable reaction mechanism.

Belousov–Zhabotinskii type oscillation reaction with glycerol and kinetics of reactions between the system components

1987 ◽  
Vol 52 (10) ◽  
pp. 2375-2382 ◽  
Author(s):  
Ľubica Adamčíková ◽  
Peter Ševčík
Keyword(s):  
Oscillation System ◽  
Chemical Oscillations ◽  
Oscillation Reaction ◽  
Reaction Solution ◽  
System Components ◽  
Probable Source ◽  
Belousov Zhabotinskii Reaction ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Type Oscillation

Glycerol causes chemical oscillations in Belousov-Zhabotinskii reaction in a closed system as well as in a reaction solution bubbled with nitrogen. Since the oxidation of glycerol with bromate ions does not proceed autocatalytically and bromine in the oxidation state 0 or +1 in the absence of light does not react with glycerol, hydrolysis of bromine is the probable source of bromide ions in the studied oscillation system.

Influence of Compressed Carbon Dioxide on the Oxidation of Cyclohexane with Hydrogen Peroxide in Acetic Acid

2006 ◽  
Vol 59 (3) ◽  
pp. 225 ◽  
Author(s):  
Liang Gao ◽  
Tao Jiang ◽  
Buxing Han ◽  
Baoning Zong ◽  
Xiaoxin Zhang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Peroxide ◽  
Acetic Acid ◽  
Binary System ◽  
Reaction System ◽  
Phase Region ◽  
Phase Behaviour ◽  
Phase System ◽  
Two Phase ◽  
Three Phase

The oxidation of cyclohexane with H2O2 in a compressed CO2/acetic acid binary system was studied at 60.0 and 80.0°C, at pressures up to 18 MPa, and with the zeolite TS-1 as catalyst. The phase behaviour of the reaction system was also observed. There are three fluid phases in the reaction system at lower pressure but two at higher pressures. In the three-phase region the yields of the products, cyclohexanol and cyclohexanone, increase considerably with increasing pressure and reaches a maximum near the phase-separating pressure. CO2 can thus enhance the reaction effectively. However, the effect of pressure on the yield is very limited after the transition to a two-phase system.

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