600-31-7Relevant academic research and scientific papers
PREREQUISITE FOR OSCILLATORY BEHAVIOUR IN THE MALONIC ACID, BROMATE AND CATALYST REACTING SYSTEMS.
Burger,Koros
, p. 363 - 366 (1980)
The role of bromomalonic acid was investigated in Belousov-Zhabotinsky systems, in the preoscillatory period. It was established that the crucial bromomalonic acid concentration (at which the trasition from non-oscillatory behavior to the oscillatory one occurs) depends on the initial reactant concentrations. This relationship is closely connected to the rate equation describing the formation of bromomalonic acid in the preoscillatory period. On the basis of the solution of the rate equation the crucial bromomalonic acid concentration can be calculated. From the temperature dependence of the rate constants, the activation energy of the bromomalonic acid formation during the preoscillatory period was calculated.
Effect of pulsed illumination on the belousov-zhabotinsky reaction catalyzed with tris(bipyridine) ruthenium(II) in continuous stirred tank reactor
Matsumura-Inoue, Takeko,Nakamura, Tatsuhito,Mori, Yoshihito,Hanazaki, Ichiro
, p. 1237 - 1238 (1999)
The photochemical response of BZ reaction with photosensitive Ru(bpy)32- has been studied under pulsed illumination in a continuous-flow stirred tank reactor, CSTR. Two types of photo-response, the advanced and delayed phase shifts of oscillation, are observed depending on the initial concentrations of malonic acid (MA) or Br- and the timing of a pulsed illumination.
Perturbation mechanism and phase transition of AOT aggregates in the Fe(II)[batho(SO3)2]3 - catalyzed aqueous Belousov-Zhabotinsky reaction
Jahan, Rumana A.,Suzuki, Kosuke,Mahara, Hitoshi,Nishimura, Satoshi,Iwatsubo, Takashi,Kaminaga, Akiko,Yamamoto, Yasuhiko,Yamaguchi, Tomohiko
, p. 304 - 308 (2010)
Surfactant AOT (sodium bis(2-ethylhexyl)sulfosuccinate) was introduced up to 200 mmol L-1 in the aqueous Belousov-Zhabotinsky (BZ) medium. Both the induction period (IP) and the oscillation period (τ) of the BZ waves decreased significantly, whereas the wave velocity (v) increased with the concentration of AOT. These tendencies were explained in terms of the perturbations to the FKN mechanism through the uptake of Br2 and BrO2· into the hydrophobic core of AOT aggregates. In addition, the structures and the phase transition of AOT aggregates were suggested based on the measurement of surface tension and the correlation analysis of the IP, τ and v values.
Electrical Pulses To Determine Chemical Phase Response Curves
Dechert, G.,Lebender, D.,Schneider, F. W.
, p. 11432 - 11435 (1995)
We report several series of single perturbation experiments in the Belousov-Zhabotinsky (BZ) reaction which have been carried out by applying an electrical current to a platinum electrode in the continuous flow stirred tank reactor (6.4 mL).When a single short current pulse is applied at the maximum of a chemical oscillation (high Ce4+ concentration) or at the minimum (low Ce4+), the response is a small advance or a significant delay of the original phase of oscillation (negative or positive phase shift), respectively.Thus we obtain phase response curves as a function of electrical current strength and duration of the pulses.These results show that the redox reactions occuring at the platinum electrodes involve mainly the Ce3+/Ce4+ redox couple as supported by pulsed additions of known Ce4+ solutions.Numerical simulations are in good agreement with the experiments.
The Potentiometric Effect of As(III) Ion on a Belousov-Zhabotinskii Oscillating Chemical Reaction. Application to the Determination of As(III)
Ojani, Reza,Raoof, Jahanbakhsh,Mahdavi, Fathemeh
, p. 2117 - 2121 (2003)
A novel analytical method that builds on specific features of non-linear chemical systems far from thermodynamic equilibrium is described. The used oscillating chemical system is the BZ (Belousove-Zhabotinskii) reaction in a non-equilibrium stationary state close to a bifurcation point. The method uses a Pt electrode for monitoring the potential response to a perturbation caused by As(III) ion. A linear response, in which the oscillating amplitude varies versus the logarithm of the As(III) concentration, was found in the range of 1.99 * 10-6-1.27 * 10-4 M. Under optimum conditions, a detection limit of 2 * 10-6 M for As(III) was obtained. The relative standard deviation (%RSD) for As(III) 1.59 * 10-5 M is 7.1 (n = 6).
Stratification in a Thin-Layered Excitable Reaction-Diffusion System with Transverse Concentration Gradients
Zhabotinsky, Anatol M.,Gyoergyi, Laszlo,Dolnik, Milos,Epstein, Irving R.
, p. 7981 - 7990 (1994)
Chemical waves propagate in thin gel layers saturated with Belousov-Zhabotinsky (BZ) reaction solution.When a layer is in contact with air, weakly interacting waves can propagate along the top and the bottom of the layer.Experiments on the ferrion-catalyzed BZ reaction with stepwise layers reveal a poorly excitable sublayer in the middle of the layer.We propose that in a BZ excitable layer open to air two opposite transverse concentration gradients are established, those of oxygen and bromine.The bromine gradient results in a parallel gradient of the total concentration of bromo derivatives of malonic acid (BrMAs).The threshold of excitability increases with the concentrations of oxygen and of BrMAs.As a result, the excitability threshold varies nonmonotonically, with a maximum in the middle of the layer.If this maximum of the excitability threshold is high enough, a poorly excitable sublayer appears between the two excitable sublayers at the top and bottom.The wave propagation and interaction have been simulated using an Oregonator-type model with a nonmonotonic vertical profile of the stoichiometric factor q that relates Br- production to ferriin reduction.The simulation confirms that the observed stratification of layers can be explained by the established mechanism of the BZ reaction supplemented with molecular diffusion.
Stoichiometry of Bromide Production from Ceric Oxidation of Bromomalonic Acid in the Belousov-Zhabotinskii Reaction
Foersterling, Horst-Dieter,Stuk, Linda,Barr, Alexander,McCormick, William D.
, p. 2623 - 2627 (1993)
We investigated the number of Ce4+ ions required to produce one Br- ion in the oxidation of bromomalonic acid by Ce4+ under conditions appropriate to the oscillating Belousov-Zhabotinskii (BZ) reaction.We found a ratio of 1:1, in agreement with earlier results by Jwo and Noyes (J.Am.Chem.Soc. 1975, 97, 5422), in the presence of oxygen.With oxygen excluded from the system, we found a ratio of 2:1.The presence of malonic acid in the system had no effect on the bromide production, contrary to the assumption of recent theoretical models of the Belousov-Zhabotinskii reaction.
Kinetics of Chemical Waves in the Acidic Bromate-Malonic Acid-Ru(bpy)32+ System in Comparison with the Ferroin System
Kuhnert, L.,Krug, H.-J.
, p. 730 - 733 (1987)
Propagation of trigger waves investigated in the acidic bromate-malonic acid-Ru(bpy)32+ system.In excitable but not oscillatory solutions the concentration dependence of wave velocity ν follows the equation ν = 2(kR1Dx)1/2()1/2 - ν0.Concentration and temperature dependence of wave velocity coincide quantitatively with the corresponding results from BZ systems containing ferroin as catalyst.In solutions with coexisting phase and trigger waves the trigger wave velocities follow the empirical law ν ca. 1.261.68.
Deuterium isotope effect on the induction period of the cerium catalyzed Belousov-Zhabotinsky reaction
Rossi, Federico,Simoncini, Eugenio,Marchettini, Nadia,Tiezzi, Enzo
, p. 147 - 150 (2009)
In this work we present results about the deuterium isotopic effect on the global kinetics of a cerium catalyzed Belousov-Zhabotinsky reaction. A nonlinear dependence of the induction period upon the percentage of deuterated reactants was found in batch conditions. In order to understand this result, we investigated two reaction pathways responsible for the length of the induction period, namely: (a) the reaction between the enolic form of the malonic acid with molecular bromine and (b) the oxidation of malonic acid by the Ce(IV) ion. In both cases we obtained a linear dependence of the kinetic constants on the percentage of deuterated reactants. Nevertheless, by inserting the experimental values in the MBM (Marburg-Budapest-Missoula) model, we were able to qualitatively simulate the observed trend of the induction period.
Measurement of Convection Velocities in "Mosaic" Patterns
Rodriguez, J.,Vidal, C.
, p. 2737 - 2740 (1989)
Experimental evidence is given of the occurence of convection in a liquid layer of an oscillatory BZ reagent, sandwiched between two glass plates.Quantitative data on the hydrodynamic velocities are reported for three different layer depths.It is shown that convective motions result from inhomogeneities spontaneously occuring in the chemical reaction.
