Dual Control Mechanism in a Belousov−Zhabotinskii (B−Z) Oscillator with Glucose and Oxalic Acid as a Double Substrate

Abstract

Oscillations in a Belousov-Zhabotinskii (B-Z) system having oxalic acid (OA) and glucose (G) as a mixed organic substrate, neither of which acts as a bromine scavenger, have been investigated. Studies have been performed for (i) varying the concentration of G while keeping the OA concentration fixed and (ii) varying OA but keeping G fixed in a batch reactor. In both cases upper and lower critical limits occur, between which oscillations are observed. Both single and double frequency oscillations have been observed in a wide range of concentrations of G as well as of OA. The induction period in most of the cases was <1 min. When G is fixed and OA is varied, the time pause between the sequential oscillations increases with an increase in OA. On the other hand when OA is fixed and G is varied, the time-pause decreases with an increase in G. The first type of oscillation is Br(-)-controlled, whereas the second is non-Br(-)-controlled. The order of addition of G and OA in the last has no influence on the induction period. It influences, however, the oscillatory characteristics. Br(2) evolution in the G + OA + Ce(4+) + BrO(3)(-) + H(2)SO(4) reaction system has been investigated spectrophotometrically. ESR and polymerization studies indicate the important role of free radicals in influencing the reaction mechanism. A tentative dual control mechanism has been suggested involving autocatalysis of HBrO(2) and BrO2*.

Growth of spherulitic crystal patterns in a Belousov–Zhabotinski type reaction system

“…Moreover, the reaction mechanism and description of pattern formations can be explained by fundamental BZ chemistry. [22][23][24][25][26][27][28][29] This suggests that, with trace amounts of Ce 4+ (or Fe 2+ ), acting as catalyst and in acidic BrO 3 À , the AA (or SA) is oxidized. Some intermediates are also formed whose concentration is found to vary periodically as a function of time.…”

Perturbation of the tris(2,2′‐bipyridine) ruthenium(II)‐catalyzed Belousov–Zhabotinsky oscillating chemiluminescence reaction by l‐cysteine and its application

“…The first report about oscillating CL reaction catalyzed by Ru(bpy) 3 2+ was proposed in 1982 by Bolletta et al, [24] which was also the first example of oscillating CL reaction in the liquid phase. However, further studies about this oscillating CL reaction have seldom been reported.…”

“…Since there are some obvious similarities between chemical oscillating systems and life processes that generally exhibit oscillatory behaviors, the investigation of the oscillating systems is of considerable interest. While a substantial number of chemical oscillators are known and have been widely used in analytical detection, [1][2][3][4][5][6][7][8][9][10][11][12][13][14] relatively few oscillating chemiluminescence (CL) reactions in the liquid phase have been described. [15][16][17][18][19][20] Recently, owing to the particular photochemical and photophysical properties of the tris(2,2′-bipyridine)ruthenium(II) [Ru(bpy) 3 2+ ] CL reagent, [21][22][23] the Ru(bpy) 3…”

Effect of Manganese Salts on an Oscillatory Chemical Reaction in Different Acid Media

“…The Marburg-Budapest-Missoula (MBM) [22] model includes both negative feedback loops (bromous acid-bromide ion Oregonator type and bromine dioxide-organic free radicals type feedback) deals only with cerium catalyzed system. A detailed study of the BZ reaction with aliphatic compounds like oxalic acid [23], malonic acid [24][25][26], citric acid [4], glucose [27], pyrocatechol [28] and ketones viz. cyclohexanone [29] and acetone [30] in wide range of concentrations of the substrates have been reported.…”