118725-10-3Relevant academic research and scientific papers
Phenylmalonic Acid Reaction with Iodine and Behavior in a Briggs-Rauscher Oscillator
Furrow, Stanley D.
, p. 2817 - 2823 (1989)
Phenylmalonic acid (PhMA) reacts via an enol mechanism with aqueous iodine to form rather reactive iodophenylmalonic acid.The rate at 25 degC in 0.1 M acid can be described by -d/dt (M s-1) = 126 /(1 + (3.8*1E4)).This iodo product can undergo hydrolysis, decarboxylation, and oxidation.Oxidants that oxidize iodide to iodine also regenerate iodine quantitatively from iodophenylmalonic acid, seemingly via an attack by HOI.When manganous ion and hydrogen peroxide are present, iodophenylmalonic acid reacts fairly rapidly by a different mechanism, giving up iodide ions.In a mixture with acidic iodate, hydrogen peroxide, and manganous ions, PhMA can serve as a substrate for a Briggs-Rauscher-type oscillating reaction.The iodo product is much less stable than the iodo product with typical Briggs-Rauscher substrates such as malonic acid or acetone, and any proposed oscillatory mechanism must be able to account for fairly rapid decomposition and iodine regeneration.
Comparison of Several Substrates in the Briggs-Rauscher Oscillating System
Furrow, Stanley D.
, p. 11131 - 11140 (1995)
Acetone, methylmalonic acid, malonic acid, iodomalonic acid, and phenylmalonic acid are compared under identical conditions in the Briggs-Rauscher oscillating system.Each of these five substrates consumes iodine to form an iodo product and produces iodide at the same time.The rates of iodine consumption have been measured for each of the substrates individually.To a first approximation, all of the substrates behave in a similar manner when compared at concentrations which react with iodine at similar rates.A skeleton model for the oscillatory system cannot quantitatively predict variations of the oscillatory period with concentration for any one of the substrates.Several reactions and processes are discussed which must be part of a complete description of the oscillator but which make only marginal improvements when compared to the skeleton model: reduction of iodate ion and iodine by hydroperoxy radical, reduction of iodate by the substrate enol, second-order reduction of iodate by iodide, next oxidation of iodine by hydrogen peroxide, continuous HOIO production, and decomposition of the iodo products.
