Role of Dibromomalonic Acid in the Photosensitivity of the Ru(bpy)<sub>3</sub><sup>2+</sup>-Catalyzed Belousov−Zhabotinsky Reaction

Vanag, Vladimir K.; Zhabotinsky, and Anatol M.; Epstein, Irving R.

doi:10.1021/jp001418m

Cited by 17 publications

(23 citation statements)

References 32 publications

(72 reference statements)

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“…The constants k M , k B , and k BB are the rate constants for the reactions of Ru(III) with malonic acid, bromomalonic acid and dibromomalonic acid, respectively; k R is the rate constant of production of BrO 2 radicals. We use the values 28 The residence time of the CSTR, k 0 -1 (where k 0 ) V f /V 0 , V f is the total flow rate through the CSTR, and V 0 is the volume of the CSTR, V 0 ) 20 mL), strongly affects the steady-state concentration of bromide ions in the CFUR. For example, when k 0 ) 10 -7 s -1 (close to a batch reactor), [Br -] SS ) 6 × 10 -9 M, while for k 0 ) 10 -3 s -1 , [Br -] SS ) 1.2 × 10 -4 M for initial concentrations corresponding to cases a-c in Table 1.…”

Section: Methodsmentioning

confidence: 99%

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

2000

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We have found a variety of oscillating patterns in the Belousov-Zhabotinsky (BZ) reaction-diffusion system with global negative feedback. Bulk oscillations and wave patterns arise at low values of the feedback strength. When the feedback exceeds a critical value, cluster patterns arise. Besides the standing, irregular, and localized clusters observed earlier, we have found new types of clusters: three-phase, localized irregular, and localized oscillatory clusters. A model of three identical Oregonators with global negative coupling yields the same bifurcation scenario as found in our experiments.

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Section: Methodsmentioning

confidence: 99%

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

2000

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“…A solution of catalyst-free BZ reaction was poured onto the gel (initial concentrations: 0.15M KBr, 0.34M malonic acid, 0.38M NaBrO 3 , and 0.48M H 2 SO 4 ). The temperature was kept constant at 25 6 1 ± C. The light intensity reaching the gel governs the system excitability through the production of Br 2 [21,22]. Images of the patterns, whose contrast was enhanced with an interference filter of 460 nm, were captured in a video recorder through a CCD camera placed vertically.…”

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confidence: 99%

Regular Wave Propagation Out of Noise in Chemical Active Media

et al. 2001

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A pacemaker, regularly emitting chemical waves, is created out of noise when an excitable photosensitive Belousov-Zhabotinsky medium, strictly unable to autonomously initiate autowaves, is forced with a spatiotemporal patterned random illumination. These experimental observations are also reproduced numerically by using a set of reaction-diffusion equations for an activator-inhibitor model, and further analytically interpreted in terms of genuine coupling effects arising from parametric fluctuations. Within the same framework we also address situations of noise-sustained propagation in subexcitable media. DOI: 10.1103/PhysRevLett.87.078302 PACS numbers: 82.40.Bj, 05.40.Ca, 47.54. +r Since their discovery thirty years ago [1], target patterns have constituted one of the most distinctive and visually compelling examples of self-organization in chemical systems. Somewhat more general, control on wave initiation and propagation may have a wealth of potential implications not only for chemical [2][3][4] or biochemical systems [5,6], but extending to cardiology [7] or neurophysiology [8] contexts. Although unavoidably present in any realistic situation of these scenarios, the minimization of noise and disorder is always pursued under the rationale that their effects may, if not destroy, at least largely mask, the intrinsic spatiotemporal regularities of any such wave propagation phenomena. Here, contrarily, we provide experimental and numerical evidence, and also an analytical explanation, of just the opposite, now beneficial, influence, by showing that an excitable chemical system may rectify external fluctuations into regularly organized wave trains. Explicitly, we will show that the photosensitive BelousovZhabotinsky (BZ) reaction [9], under excitable conditions unable to create autowaves, does maintain a target structure when subjected to a patterned and continuously evolving random illumination.Moreover a theoretical framework for activatorinhibitor models will be proposed to interpret not only this experimental finding but the recent related one of noisesupported waves in subexcitable media [10]. With this 078302-10031-9007͞01͞ 87(7)͞078302(4)$15.00

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“…Ru͑bpy͒ 3 2+ as a catalyst 39 plays an important role in the investigation of self-organizing dynamics in the presence of light 40 as an external control parameter. 47 we use the values K 1 = 4.0 ϫ 10 −5 M and ͓H + ͔ = 0.5M. 41 Several mechanisms have been proposed to account for the light sensitivity of the Ru͑bpy͒ 3 2+ -catalyzed BZ reaction.…”

Section: Construction Of a Detailed Photo-bz Modelmentioning

confidence: 99%

“…This rutheniumcatalyzed system has become increasingly important during the last years, particularly in studies related to external control of the system dynamics by modifying the medium's excitability through adjusting the illumination intensity. 47 we have also included the role of dibromomalonic acid ͑Br 2 MA͒ in the photosensitivity of the BZ system ͑R9͒. [42][43][44] These consist of a number of elementary reaction steps for most of which kinetic parameters are available from experimental data.…”

Section: Construction Of a Detailed Photo-bz Modelmentioning

confidence: 99%

Derivation of a quantitative minimal model from a detailed elementary-step mechanism supported by mathematical coupling analysis

Shaik

Kammerer

Górecki

et al. 2005

The Journal of Chemical Physics

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Accurate experimental data increasingly allow the development of detailed elementary-step mechanisms for complex chemical and biochemical reaction systems. Model reduction techniques are widely applied to obtain representations in lower-dimensional phase space which are more suitable for mathematical analysis, efficient numerical simulation, and model-based control tasks. Here, we exploit a recently implemented numerical algorithm for error-controlled computation of the minimum dimension required for a still accurate reduced mechanism based on automatic time scale decomposition and relaxation of fast modes. We determine species contributions to the active (slow) dynamical modes of the reaction system and exploit this information in combination with quasi-steady-state and partial-equilibrium approximations for explicit model reduction of a novel detailed chemical mechanism for the Ru-catalyzed light-sensitive Belousov-Zhabotinsky reaction. The existence of a minimum dimension of seven is demonstrated to be mandatory for the reduced model to show good quantitative consistency with the full model in numerical simulations. We derive such a maximally reduced seven-variable model from the detailed elementary-step mechanism and demonstrate that it reproduces quantitatively accurately the dynamical features of the full model within a given accuracy tolerance.

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Role of Dibromomalonic Acid in the Photosensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction

Cited by 17 publications

References 32 publications

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

Regular Wave Propagation Out of Noise in Chemical Active Media

Derivation of a quantitative minimal model from a detailed elementary-step mechanism supported by mathematical coupling analysis

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Role of Dibromomalonic Acid in the Photosensitivity of the Ru(bpy)32+-Catalyzed Belousov−Zhabotinsky Reaction

Cited by 17 publications

References 32 publications

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

Pattern Formation in the Belousov−Zhabotinsky Reaction with Photochemical Global Feedback

Regular Wave Propagation Out of Noise in Chemical Active Media

Derivation of a quantitative minimal model from a detailed elementary-step mechanism supported by mathematical coupling analysis

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Role of Dibromomalonic Acid in the Photosensitivity of the Ru(bpy)₃²⁺-Catalyzed Belousov−Zhabotinsky Reaction