HPLC Studies on the Organic Subset of the Oscillatory BZ Reaction. 3. Products of the Ce~(4+)-Bromomalonic Acid Reaction

摘要

Using HPLC technique, two different pathways were found for the oxidation of bromomalonic acid by Ce~(4+). One route is dominant when the Ce~(4+) concentration is low compared to that of bromomalonic acid (BrMA). The end products of this reaction route are bromoethenetricarboxylic acid (BrEETRA), CO_2, and Br~-. For this route two slightly different mechanisms (both are based on radical-radical recombination reactions) are proposed, which can explain the formation of BrEETRA. The other pathway is dominant when Ce~(4+) is in excess. This route leads to a compete oxidation of BrMA to CO_2. No intermediates of this route were found, however.