Kinetics and Mechanism of Ce(IV) Oxidation of Free and Coordinated Glyoxylic Acid

Article abstract of DOI:10.1246/bcsj.58.3597

The kinetics and mechanism of Ce(IV) oxidation of glyoxylic acid and pentaammineglyoxalatocobalt(III) perchlorate have been investigated in acidic sulfate media in the temperature range 35 to 50 deg C and at ionic strength 0.95 M.The rate of decrease of was found to be first order in and .The observed second order rate constant, k_obsd, for the disappearance of is satisfactorily given by, k_obsd = 1 + k₂K₃4^->/+>>/<1 + K₃4^->/+>> (for glyoxylato complex) and k_obsd = k₁/<1 + K₃4^->/+>> (for glyoxylic acid).Both Ce(SO₄)₂ and 4)₃)^2- appear to be the oxidant species for coordinated glyoxylate while for free glyoxilic acid Ce(SO₄)₂ seems to be the only oxidant species.The values of k₁ and k₂ and the associated activation parameters have been computed.A suitable mechanism has been suggested for the reaction.