β‐Cyclodextrin‐catalyzed decomposition of Caro's acid

The kinetics and mechanism of decomposition of peroxomonosulphate (PMS) in aqueous sodium hydroxide medium in the presence β‐cyclodextrin has been investigated. The rate of decomposition of PMS is considerably enhanced by the added β‐cyclodextrin. The reaction follows first order kinetics with respect to [PMS]. The experimental results suggest the formation of β‐cyclodextrin peroxy anion by the interaction between SO₅^2?, and β‐cyclodextrin anion (BCDO^?). β‐Cyclodextrin peroxy anion subsequently reacts with PMS to give O₂, SO₄^2? and β‐cyclodextrin anion. The rate constant for the β‐cyclodextrin‐catalyzed decomposition of SO₅^2? (BCD + SO₅^2?) is of the same order of magnitude as that of the reaction HSO₅^2? + SO₅^2? products. © 2002 Wiley Periodic mals, Inc. Int J Chem Kinet 34: 508–513, 2002