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Barnes EO, Wang Y, Limon-Petersen JG, Belding SR, Compton RG. Voltammetry in the absence of excess supporting electrolyte – ECE-DISP1 reactions: The electrochemical reduction of 2-nitrobromobenzene in acetonitrile solvent. J Electroanal Chem (Lausanne) 2011. [DOI: 10.1016/j.jelechem.2011.04.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wain AJ, Compton RG, Le Roux R, Matthews S, Fisher AC. Microfluidic Channel Flow Cell for Simultaneous Cryoelectrochemical Electron Spin Resonance. Anal Chem 2007; 79:1865-73. [PMID: 17269792 DOI: 10.1021/ac061910n] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A novel microfluidic electrochemical channel flow cell has been constructed for in situ operation in a cylindrical TE011 resonant ESR cavity under variable temperature conditions. The cell has a U-tube configuration, consisting of an inlet and outlet channel which run parallel and contain evaporated gold film working, pseudo-reference, and counter electrodes. This geometry was employed to permit use in conjunction with variable temperature apparatus which does not allow a flow-through approach. The cell is characterized qualitatively and quantitatively using the one-electron reduction of p-bromonitrobenzene in acetonitrile at room temperature as a model system, and the ESR signal-flow rate response is validated by use of three-dimensional digital simulation of the concentration profile for a stable electrogenerated radical species under hydrodynamic conditions. The cell is then used to obtain ESR spectra for a number of radical species in acetonitrile at 233 K, including the radical anions of m- and p-iodonitrobenzene, o-bromonitrobenzene, and m-nitrobenzyl chloride, the latter three being unstable at room temperature. Spectra are also presented for the radical anion of 2-chloranthraquinone and the crystal violet radical, which display improved resolution at low temperatures.
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Affiliation(s)
- Andrew J Wain
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, UK
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Hydrodynamic cryoelectrochemical ESR: The reduction of ortho-bromonitrobenzene in acetonitrile. J Electroanal Chem (Lausanne) 2006. [DOI: 10.1016/j.jelechem.2005.11.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Tsai YC, Coles BA, Compton RG, Marken F. Microwave activation of electrochemical processes: enhanced electrodehalogenation in organic solvent media. J Am Chem Soc 2002; 124:9784-8. [PMID: 12175237 DOI: 10.1021/ja026037w] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The effect of high-intensity microwave radiation focused into a "hot spot" region in the vicinity of an electrode on electrochemical processes with and without coupled chemical reaction steps has been investigated in organic solvent media. First, the electrochemically reversible oxidation of ferrocene in acetonitrile and DMF is shown to be affected by microwave-induced thermal activation, resulting in increased currents and voltammetric wave shape effects. A FIDAP simulation investigation allows quantitative insight into the temperature distribution and concentration gradients at the electrode / solution interface. Next, the effect of intense microwave radiation on electroorganic reactions is considered for the case of ECE processes. Experimental data for the reduction of p-bromonitrobenzene, o-bromonitrobenzene, and m-iodonitrobenzene in DMF and acetonitrile are analyzed in terms of an electron transfer (E), followed by a chemical dehalogenation step (C), and finally followed by another electron-transfer step (E). The presence of the "hot spot" in the solution phase favors processes with high activation barriers.
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Affiliation(s)
- Yu-Chen Tsai
- Physical and Theoretical Chemistry Laboratory, Oxford University, Oxford OX1 3QZ, United Kingdom
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BALL JC, COMPTON RG. Application of Ultrasound to Electrochemical Measurements and Analyses. ELECTROCHEMISTRY 1999. [DOI: 10.5796/electrochemistry.67.912] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Jacob SR, Hong Q, Coles BA, Compton RG. Variable-Temperature Microelectrode Voltammetry: Application to Diffusion Coefficients and Electrode Reaction Mechanisms. J Phys Chem B 1999. [DOI: 10.1021/jp990024w] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sarah R. Jacob
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, U.K
| | - Qi Hong
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, U.K
| | - Barry A. Coles
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, U.K
| | - Richard G. Compton
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, OX1 3QZ, U.K
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Prieto F, Aixill WJ, Alden JA, Coles BA, Compton RG. Voltammetry under High Mass Transport Conditions. The High-Speed Channel Electrode and Transient Measurements. J Phys Chem B 1997. [DOI: 10.1021/jp970307t] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Francisco Prieto
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - W. Joanne Aixill
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - John A. Alden
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Barry A. Coles
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Richard G. Compton
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
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Williams DE, Ellis K, Colville A, Dennison SJ, Laguillo G, Larsen J. Hydrodynamic modulation using vibrating electrodes: Application to electroanalysis. J Electroanal Chem (Lausanne) 1997. [DOI: 10.1016/s0022-0728(97)00214-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Leslie WM, Alden JA, Compton RG, Silk T. ECE and DISP Processes at Channel Electrodes: Analytical Theory. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960975z] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Wayne M. Leslie
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - John A. Alden
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Richard G. Compton
- Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Toomas Silk
- Faculty of Physics and Chemistry, Tartu University, Jakobi 2, EE2400 Tartu, Estonia
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Alden JA, Compton RG, Dryfe RAW. Modelling electrode transients: the strongly implicit procedure. J APPL ELECTROCHEM 1996. [DOI: 10.1007/bf00683749] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Anderson JL, Bowden EF, Pickup PG. Dynamic Electrochemistry: Methodology and Application. Anal Chem 1996. [DOI: 10.1021/a1960015y] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James L. Anderson
- Department of Chemistry, University of Georgia, Athens, Georgia 30602
| | - Edmond F. Bowden
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - Peter G. Pickup
- Department of Chemistry, Memorial University of Newfoundland, St. John's, Newfoundland, Canada A1B 3X7
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The reduction ofm-iodo-nitrobenzene: A comparative study using microdisk and channel electrodes. ELECTROANAL 1996. [DOI: 10.1002/elan.1140080303] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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The photoelectrochemical reduction of p-bromo-nitrobenzene: An ECEE, ECE or DISP process? Mechanistic resolution via channel electrode voltammetry. J Electroanal Chem (Lausanne) 1994. [DOI: 10.1016/0022-0728(94)03384-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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