Spectrophotometric study of the BrO 3 − /Ce4+/1,3-cyclohexanedione oscillating system

Complex kinetics and significant influences of bromine removal in ferroin–bromate–metol reaction

“…The solution was extracted after 60 000s with diethylether. A 1 H NMR resonance at d = 6.79 is attributable to 1,4-benzoquinone (BQ), this was further supported by the 13 C NMR spectral resonances at 136.6 and 187.4 ppm (see ESIw). The 1 H NMR spectral resonances appearing at d = 7.31 (d, J = 2.3 Hz); 6.95 (d, J = 10.1 Hz); and 6.84 (dd, J = 10.1, 2.3 Hz) correspond to the product 2-bromo-1,4-benzoquinone (BrQ).…”

“…Mass spectrometric measurements were carried out with Electrospray Ionization Time-of-Flight Mass Spectrometer and a 1200 L single quadruple MS (Varian) through a direct insertion probe. All 1 H-NMR and 13 C-NMR studies were performed using a Bruker Avance 500 MHz spectrometer and with the same sample that was used for mass spectrometry studies, but dissolved in deuterated chloroform (Cambridge Isotope Laboratories, 99.8%). In (a), volatile substances, mainly bromine molecules, were prevented from migrating out of the reactor, and no spontaneous oscillations took place.…”

“…Since the discovery of the Belousov-Zhabotinsky (BZ) reaction, [1][2][3] a large family of bromate-based chemical oscillators have been uncovered over the past three decades, including both catalyzed and uncatalyzed systems. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The majority of those bromate oscillators are the replacement of malonic acid of the BZ reaction by different organic substrates. [7][8][9][10][11][12][13][14][15][16][17][18] When malonic acid is replaced, the consumption rate of bromine molecules and the production paths of bromide ions, that modulate the autocatalytic feedback cycles, are alternated.…”

“…[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] The majority of those bromate oscillators are the replacement of malonic acid of the BZ reaction by different organic substrates. [7][8][9][10][11][12][13][14][15][16][17][18] When malonic acid is replaced, the consumption rate of bromine molecules and the production paths of bromide ions, that modulate the autocatalytic feedback cycles, are alternated. 19 As a result, those modified BZ systems may exhibit very different reaction behavior.…”

Complex Dynamical Behavior in the Highly Photosensitive Cerium–Bromate–1,4-Benzoquinone Reaction

“…Reactions between bromate and organic substrates in an acidic solution with or without the assistance of metal catalysts have been extensively investigated in the context of nonlinear chemical dynamics in which the overall process can be characterized as the oxidation and bromination of the organic substrate. − The frequently employed catalysts include ferroin, ruthenium complexes, cerium, and manganese. , The oxidation of the substrate, taking place through its reaction with the oxidized catalyst, − is largely responsible for the regeneration of the reduced metal catalysts for the autocatalytic processes. The recycling of the metal catalysts ensures that continuous oscillations can exist in bromate-based chemical oscillators such as the Belousov–Zhabotinsky (BZ) oscillator.…”