Kinetics and mechanism of oxidation of indole by HSO

Abstract

Mechanistic studies on the oxidation of indole [IND] by HSO − 5 in aqueous CH 3 CN medium (80:20 v/v) have been carried out, and the reaction is characterized by the rate law −d[HSO − 5 ]/dt = k[IND][HSO − 5 ]HSO − 5 and SO 2− 5 are probably the respective electrophiles in acidic and basic mediums. Nucleophilic attack of the ethylenic bond on the persulfate oxygen is envisaged to explain the reactivity. The reaction fails to initiate polymerization, and a radical mechanism is ruled out. Thermodynamic parameters very much suggest a bimolecular process. No significant catalytic activity is observed for the reaction system in the presence of Ag +

Kinetics and mechanism of meso-tetraphenylporphyriniron(III) chloride (TPP) catalysed oxidation of indole by sodium perborate

“…6). This type of product was already reported 9 . The oxygen transfer step is associated with large negative value of entropies of activation and signifi cant enthalpies of activation.…”

“…Rangappa et al 8 have examined the kinetics of oxidation of indole by chloramines-T in the presence of Os(VIII) in alkaline medium. Peroxomonosulphate can also be used to convert indoles to oxindoles 9 . Sodium perborate, a peroxo salt of anionic formula: B 2 (O 2 ) 2 -(OH) 4 2-, is a cheap, non-toxic, stable, easily handled, large scale industrial chemical, mostly used in detergents as a bleaching agent.…”

Kinetics and Mechanism of Meso-Tetraphenylporphyriniron(iii) Chloride (Tpp) Catalysed Oxidation of Indole by Magnesiummono Peroxyphthalate

“…6). This type of product was already reported 9 . The oxygen transfer step is associated with large negative value of entropies of activation and significant enthalpies of activation.…”

“…Rangappa et al 8 have examined the kinetics of oxidation of indole by chloramines-T in the presence of Os(VIII) in alkaline medium. Peroxomonosulphate can also used to convert indoles to oxindoles 9 . Among the oxygen donors, towards oxidation, magnesium monoperoxyphthalate (MMPP) was recently found to be a very efficient oxidant 10 .…”

Kinetics of Ag(I) catalyzed oxidation of amino acids by peroxomonosulphate

“…It is also proved to be a strong oxidizing agent compared to other traditional reagents like peroxodisulphate and peroxomonophosphoric acid [16][17][18][19][20][21]. The predominant reactive species of PMS in acidic medium is HSO À 5 and it is more reactive than SO 2À 5 .…”