Alternative Reaction Channels and Carbene Intermediates in the Ce4+-Malonic Acid and Ce4+-Bromomalonic Acid Reactions. 1. CO2 Measurements.
Alternative Reaction Channels and Carbene Intermediates in the Ce4+-Malonic Acid and Ce4+-Bromomalonic Acid Reactions. 1. CO2 Measurements.
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DOI：
10.1021/jp990330
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发表时间：
1999-06
期刊：
影响因子：
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通讯作者：
Szilveszter Nagygyory;M. Wittmann;Szilveszter Pintér;A. Visegrády;A. Dancsó;Nguyen Thi Bich Thuy;Z. Noszticzius;L. Hegedüs;H. Försterling
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文献类型：
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作者：
Szilveszter Nagygyory;M. Wittmann;Szilveszter Pintér;A. Visegrády;A. Dancsó;Nguyen Thi Bich Thuy;Z. Noszticzius;L. Hegedüs;H. Försterling
The Ce4+-malonic/bromomalonic acid reactions play an important role in the oscillatory Belousov-Zhabotinsky reaction. In this work CO2 evolution from these reactions was studied with a sensitive and quantitative method, by converting the CO2 to methane and measuring it with a flame ionization detector. It was found that the stoichiometries depend on the initial conditions in batch experiments or on the mixing rate of reagents in a semibatch reactor. These findings are explained by two main reaction channels: one for recombination and another for decarboxylation. Decarboxylation itself has two separate routes, one is dominant at low while the other at high Ce4+ concentrations. In the latter, formation of more than two CO2 molecules from one malonic/bromomalonic acid molecule was observed. Novel reaction schemes containing carbenes are proposed for these "high Ce4+" decarboxylation channels. To check the new mechanism, HPLC measurements are planned as a continuation of the research.
