Oxidation of Glyoxylic Acid to Formic Acid in the Belousov-Zhabotinsky Reaction. A 1H NMR Study

Article abstract of DOI:10.1021/j100296a058

We describe experimental evidence obtained by ¹H NMR spectroscopy which shows that, when a malonic acid BZ reaction is perturbed by glyoxylic acid in the concentration range 10^-1-10^-3 M, the production of formic acid is observed.Since the oscillator without added glyoxylic acid does not show any production of formic acid, and since formic acid itself was found to be inert when added to a BZ system, we beleive that glyoxylic acid cannot be a major intermediate in the malonic acid BZ reaction.Also when hydroxyacetic acid is added in the concentration range 10^-1-10^-2 M to a malonic acid BZ reaction formic acid was found as an end product.These results indicate that glyoxylic acid is not an intermediate in the malonic acid BZ reaction and we suggest a reaction path for malonic acid oxidation under BZ conditions starting from malonic acid via tartronic acid to mesoxalic acid and finally to carbon dioxide.We also show that the recently proposed hydrogen sulfite test to determine quantitatively glyoxylic acid in the BZ reaction is not specific for this compound: also mesoxalic acid reacts almost quantitatively with the hydrogen sulfite ion.