Kinetics and mechanism of the oxidation of dimethyl, dipropyl and diphenyl sulfides by benzimidazolium dichromate
| Main Authors: | Dinesh Pandey, Seema Kothari |
|---|---|
| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 2015
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/5598791 |
Daftar Isi:
- Department of Chemistry, JNV University, Jodhpur-342 005, Rajasthan, India E-mail : seemakothari23@gmail.com Department of Chemistry, MLS University, Udaipur-313 001, Rajasthan, India Manuscript received online 03 November 2014, revised 25 December 2014, accepted 31 December 2014 The oxidation of dimethyl-, dipropyl- and diphenyl sulfides by benzimidazolium dichromate (BIDC) in dimethyl sulfoxide, to the corresponding sulfoxides, is first order with respect to BIDC. Michaelis-Menten type kinetics were observed with respect to sulfide. The reaction is catalysed by hydrogen ions and the order is less than one. It appears that the BIDC-H+ is the active electrophile. An intermediate of composition Sulfide-BIDC-H+ has envisaged. An analysis of the solvent effect by Swain’s equation indicated that though both the anion- and cation-solvating powers of the solvent contribute to the observed solvent effect, the role of cation-solvation is major. A mechanism involving the rate-determining oxygen atom transfer within complex, formed by a nucleophilic attack of sulfide-sulfur on BIDCH+ in a rapid pre-equilibrium, is suggested to give product via a cyclic transition state.