Catalyst, Co-ion and the media effect on the oscillatory behavior of resorcinol in the BZ reaction

Abstract

O estudo diz respeito ao comportamento oscilatório de resorcinol como substrato orgânico na reação de Belousov-Zhabotinsky (BZ) em presença de diferentes íons metálicos como catalisadores no meio aquoso ácido. ). On varying the aqueous acid media, it is observed that protonated species with respect to organic substrate (resorcinol) is more easily formed in aqueous sulfuric acid, owing to which maximum number of oscillations are observed in this medium. Moreover, the effect of different anions like acetate, carbonate and sulfate associated with the same metal ion (Mn 2+ ) as catalyst on the oscillatory behavior of the reaction system was also studied. Mixed mode oscillations are seen while changing concentration of aqueous sulfuric acid medium.

Effect of Different Counterions of the Manganese Salt as Catalyst on the Kinetics of Resorcinol‐Based Belousov–Zhabotinsky Reaction

“…It is mentioned that some minimal oscillations have been observed for the systems containing higher concentrations of acetylacetonate in the absence of main substrate, i.e., resorcinol. This is a prelude to the aforesaid statement that organic species used as counterions can avoid the use of organic substrates in the catalyzed BZ system. However, this is in contradiction to the bromine‐scavenging role of acetylacetonate .…”

“…The reaction systems were studied at 30 ± 0.1°C, and 1.3 mol L −1 sulfuric acid was used as the medium throughout. In the first instance, an attempt was made to choose the metal ion for which good trials of the reaction systems were made with Mn 2+ , Ce 3+ , Ce 4+ , and Fe(phen) 3 2+ ions as catalysts in the form of most stable salts, and it was observed that prominent oscillations are apparent with Mn 2+ ion as compared to the other metal ions . Thus, Mn 2+ ion was chosen as the catalyst and 10 manganese salts varying in the nature of anionic moieties were used later to study the effect of the anionic moieties associated with the manganese ion as the catalyst on the oscillatory characteristics of the reaction systems.…”

Dynamical regime of resorcinol based Belousov–Zhabotinsky chemical oscillator in the presence or absence of some hydrophobic antioxidants in aqueous–organic mixed media

“…Except bromate solution, all the BZ reagent solutions including that of antioxidants of suitable concentrations were prepared in organicaqueous acid mixed media, to avoid the direct early reaction of the former, as bromate is responsible for bromination of the organic solvent as well. As reported in our previous papers 46,47 also, for potentiometric studies, the volumes of initial reagents which are mixed in a proper sequence (resorcinol and metal rst followed by bromate) are 2 mL each, wherein, bromate solution is always added last out of the BZ reagents.…”

“…During this study, we have worked on several organic-aqueous mixed media to evaluate the best one that can be used for deterministic studies in future. Here, four hydrophobic biologically important antioxidants have been used as perturbants, solubilized by these non aqueous mixed media under unstirred batch conditions, as was the case with resorcinol as substrate in our previous works [46][47][48] and this has opened a new chapter to carry out the investigations with similar other hydrophobic species in future. The resorcinol has been chosen owing to its sufficient solubility in aqueous acid medium and dynamic behavior over a wide range of concentrations.…”

Kinetics of the Acetaminophen-Based Oscillatory Chemical Reaction with and without Ferroin as Catalyst: An Inorganic Prototype Model for Acetaminophen–Ethanol Syndrome

“…Temperature plays an important role in the dynamics of BZ reactions. A number of studies describe the influence of temperature on BZ reactions [46][47][48][49][50]. Körös first reported the dependence of oscillatory frequency on temperature [22].…”