Abstract: | The kinetics of the oxidation of styrene, cinnamic acid, and some of their substituted derivatives by hexachloroiridate(IV) in dimethyl formamide–water mixtures and in the presence of perchloric acid have been investigated. The reactions appear to proceed via the formation of an unstable intermediate 1:1 complex between iridium(IV) and the substrate, followed by the decomposition of the complex in the rate‐determining step. Correlation with σ yielded ρ values of ?4.0 and ?3.5 which suggests the formation of a cationic intermediate in the rate‐determining step of the reaction. Subsequent cleavage of the carbon–carbon bond yielded the product aldehydes. Thermodynamic and activation parameters associated with the equilibrium and the rate‐determining steps were also evaluated. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 411–417, 2002 |