β‐Cyclodextrin‐catalyzed decomposition of Caro's acid

Abstract

The kinetics and mechanism of decomposition of peroxomonosulphate (PMS) in aqueous sodium hydroxide medium in the presence of 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 SO 5 2− , and β-cyclodextrin anion (BCDO − ). β-Cyclodextrin peroxy anion subsequently reacts with PMS to give O 2 , SO 4 2− and β-cyclodextrin anion. The rate constant for the β-cyclodextrin-catalyzed decomposition of SO 5 2− (BCD + SO 5 2− ) is of the same order of magnitude as that of the reaction HSO 5 2− + SO 5

Kinetic evidence for the copper peroxide intermediate with two copper ions in proximity

“…Ball and Edwards 7 observed a fast reaction between Caro's acid and hydrogen peroxide above pH 10, and analogous to mechanism II the reaction involves the attack on one of the oxygen of H 2 O 2 26. The decomposition of caroate in alkaline medium is catalyzed by β‐cyclodextrin 27, and the experimental results favor a mechanism of the interaction of β‐cyclodextrin peroxide anion with SO. These observations suggest that the interaction of SO with the oxygen of peroxide or peroxide anion (negatively charged) leads to the enhanced decomposition of caroate.…”

Microheterogeneous Catalysis

“…The effects of cyclodextrins on electron transfer processes have been considered above. The effects of these kinds of receptors on biomimetic reactions have been reviewed [ 99 ] as well as studies of cyclodextrin effects on organic reactions [ 100 , 101 , 102 , 103 , 104 , 105 , 106 ], redox reactions [ 107 , 108 , 109 ], ligand substitution reactions [ 110 ], etc. , in such a way that the effects of this kind of catalyst on practically any type of reaction have been studied.…”