Insight into the formation of organosulfur compounds from the reaction of methyl vinyl ketone with sulfite radical in atmospheric aqueous phase

The formation of organosulfur compounds through the reaction of organic specieswith sulfoxy radicals produced fromthemetal-catalyzed oxidation of S(IV) has become of recent concern, but the detailed formation mechanism still remains unanswered. In this work, we studied the mechanism of the initial reaction of methyl vinyl ketone (MVK) by SO3- radical and the subsequent sulfonate formation processes using DFT calculation. The results show that dissolved O-2 addition to the initial product ismore favorable than the addition ofMVK to the initial product due to its lower activation free energy (6.19 kcalmol(-1)). The produced peroxyl radical can undergo bimolecular self-reactions, unimolecular decay and bimolecular reaction with other species (HSO3- and H2O) to form alcohols and ketones. Among them, two pathways are most likely to occur: one belongs to bimolecular self-reactions, whose activation free energy is 16.20 kcal mol(-1); the other is derived from bimolecular reaction of peroxyl radical with HSO3-, which needs to overcome the activation free energy of 18.47 kcal mol(-1). This work displays a complete description of the formation process of sulfonates and thus can provide some insights into the further study on the formation of organosulfur compounds. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study investigated the initial reaction mechanism of methyl vinyl ketone (MVK) by SO3- radicals and the subsequent sulfonate formation processes using DFT calculation. The results showed that dissolved O-2 addition to the initial product is more favorable. The produced peroxyl radical can form alcohols and ketones through bimolecular self-reactions and bimolecular reactions with other species such as HSO3-.