A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes
The oxidation of bromide has been investigated by linear sweep and cyclic voltammetry at platinum electrodes in the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, ([C 4mim][NTf 2]), and the conventional aprotic solvent, acetonitrile, (MeCN). Similar vo...
| Main Authors: | , , , , |
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| Format: | Journal article |
| Language: | English |
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2005
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| _version_ | 1797060425417752576 |
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| author | Allen, G Buzzeo, M Villagran, C Hardacre, C Compton, R |
| author_facet | Allen, G Buzzeo, M Villagran, C Hardacre, C Compton, R |
| author_sort | Allen, G |
| collection | OXFORD |
| description | The oxidation of bromide has been investigated by linear sweep and cyclic voltammetry at platinum electrodes in the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, ([C 4mim][NTf 2]), and the conventional aprotic solvent, acetonitrile, (MeCN). Similar voltammetry was observed in both solvents, despite their viscosities differing by more than an order of magnitude. DigiSim ® was employed to simulate the voltammetric response. The mechanism is believed to involve the direct oxidation of bromide to bromine in a heterogeneous step, followed by a homogenous reaction to form the tribromide anion:2Br-→Br2+2e-Br2+Br-→kbkfBr3-KeqAthigher potentials, the tribromide anion dissociates to bromine, Br 2, and bromide, Br -, which is immediately oxidised, leading to the emergence of a second anodic wave. Irreversible electrode kinetics were inferred from Tafel analysis and removal of the first electron is believed to be the rate-determining step in the formation of bromine. The equilibrium constant, K eq, whereKeq=[Br3-][Br2][Br-]was found to be 3 × 10 3 and 9 × 10 6 M -1 in the ionic liquid and in acetonitrile, respectively. An equilibrium constant, K complex for the complexation of 1-ethyl-3-methylimidazolium bromide in acetonitrile was found to be 35.1 M -1. © 2004 Elsevier B.V. All rights reserved. |
| first_indexed | 2024-03-06T20:16:56Z |
| format | Journal article |
| id | oxford-uuid:2c7043f1-1d82-407f-a37f-65ea83470ed9 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T20:16:56Z |
| publishDate | 2005 |
| record_format | dspace |
| spelling | oxford-uuid:2c7043f1-1d82-407f-a37f-65ea83470ed92022-03-26T12:37:14ZA mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:2c7043f1-1d82-407f-a37f-65ea83470ed9EnglishSymplectic Elements at Oxford2005Allen, GBuzzeo, MVillagran, CHardacre, CCompton, RThe oxidation of bromide has been investigated by linear sweep and cyclic voltammetry at platinum electrodes in the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide, ([C 4mim][NTf 2]), and the conventional aprotic solvent, acetonitrile, (MeCN). Similar voltammetry was observed in both solvents, despite their viscosities differing by more than an order of magnitude. DigiSim ® was employed to simulate the voltammetric response. The mechanism is believed to involve the direct oxidation of bromide to bromine in a heterogeneous step, followed by a homogenous reaction to form the tribromide anion:2Br-→Br2+2e-Br2+Br-→kbkfBr3-KeqAthigher potentials, the tribromide anion dissociates to bromine, Br 2, and bromide, Br -, which is immediately oxidised, leading to the emergence of a second anodic wave. Irreversible electrode kinetics were inferred from Tafel analysis and removal of the first electron is believed to be the rate-determining step in the formation of bromine. The equilibrium constant, K eq, whereKeq=[Br3-][Br2][Br-]was found to be 3 × 10 3 and 9 × 10 6 M -1 in the ionic liquid and in acetonitrile, respectively. An equilibrium constant, K complex for the complexation of 1-ethyl-3-methylimidazolium bromide in acetonitrile was found to be 35.1 M -1. © 2004 Elsevier B.V. All rights reserved. |
| spellingShingle | Allen, G Buzzeo, M Villagran, C Hardacre, C Compton, R A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title | A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title_full | A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title_fullStr | A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title_full_unstemmed | A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title_short | A mechanistic study of the electro-oxidation of bromide in acetonitrile and the room temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide at platinum electrodes |
| title_sort | mechanistic study of the electro oxidation of bromide in acetonitrile and the room temperature ionic liquid 1 butyl 3 methylimidazolium bis trifluoromethylsulfonyl imide at platinum electrodes |
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