Kinetics of the oxidation of cyclohexene by thallium(III) acetate

✍ Scribed by Leon F. Loucks; Michael T. H. Liu; Danny K. Durant

• Publisher: John Wiley and Sons
• Year: 1985
• Tongue: English
• Weight: 553 KB
• Volume: 17
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550170602

✦ Synopsis

Abstract

The kinetics of the reaction by which thallium(III) acetate oxidizes cyclohexene in glacial acetic acid medium, has been studied by UV spectrophotometric observation at 30°C. The consumption of thallium(III) acetate follows a second‐order rate law exhibiting first‐order dependence on each of thallium(III) acetate and cyclohexene; however, the first‐order dependence on cyclohexene disappears at high cyclohexene concentrations as pseudo‐first‐order conditions prevail above 0.2 M cyclohexene. A steady‐state model of the following form is proposed:
equation image
where Tl, Cy, and Com are units of Thallium(III) acetate, cyclohexene, and a reaction complex. The value of k~2~ has been evaluated as 0.00027 and (k~−1~ + k~2~) as 0.0385__k__~1~. For low thallium(III) acetate concentrations the reaction kinetics follow the rate law:
where α = the excess concentration of cyclohexene over thallium(III) triacetate. For thallium(III) acetate concentrations above 0.02 M, double salt formation of thallium(III) acetate with product thallium(I) acetate removes thallium(III) acetate from the reaction and a modified rate law is observed. Runge–Kutta numerical solutions to the differential equations provide confirmation that the rate expressions are valid in predicting the observed concentrations of thallium(III) acetate.