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Prediction of the pH‐rate profile for dimethyl sulfide oxidation by hydrogen peroxide: The role of elusive H 3 O 2 + Ion
Author(s) -
Silva Carlos M.,
Silva Poliana L.,
Pliego Josefredo R.
Publication year - 2013
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.24594
Subject(s) - chemistry , hydrogen peroxide , kinetics , aqueous solution , dimethyl sulfide , ab initio , hydrogen sulfide , sulfide , inorganic chemistry , ion , aqueous medium , cluster (spacecraft) , chemical kinetics , computational chemistry , organic chemistry , sulfur , physics , quantum mechanics , computer science , programming language
Experimental kinetics of sulfide oxidation by hydrogen peroxide presents a pH‐dependent profile. In this article, it was carried out a detailed study of the mechanism and kinetics of dimethyl sulfide (DMS) oxidation by H 2 O 2 in neutral, acid, and basic aqueous medium using ab initio calculations. The results point out that DMS oxidation in neutral aqueous medium occurs through its direct reaction with H 2 O 2 . In acid medium, cluster‐continuum model calculations shows thatH 3 O + ( H 2 O 2 ) ( H 2 O ) 2cluster is the best representation of the very reactiveH 3 O 2+species. In basic medium, there is formation of theHO 2 −species. However, the pathway involving this species has high free energy barrier, making this pathway unfeasible. The theoretical pH‐rate profile is in good agreement with the experimental observations. © 2013 Wiley Periodicals, Inc.