Modeling Diffusion Effects for a Stepwise Two-Electron Reduction Process at a Microelectrode: Study of the Reduction of para-Quaterphenyl in Tetrahydrofuran and Inference of Fast Comproportionation of the Dianion with the Neutral Parent Molecule

被引:22
作者
Belding, Stephen R. [1 ]
Baron, Ronan [1 ]
Dickinson, Edmund J. F. [1 ]
Compton, Richard G. [1 ]
机构
[1] Univ Oxford, Dept Chem, Phys & Theoret Chem Lab, Oxford OX1 3QZ, England
基金
英国工程与自然科学研究理事会;
关键词
TEMPERATURE IONIC LIQUIDS; COMPLEX EQUILIBRIA; MICRODISK ELECTRODES; COEFFICIENTS; ANION; ELECTROCHEMISTRY; VOLTAMMETRY; PLATINUM; KINETICS;
D O I
10.1021/jp906323n
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
This paper presents a study of voltammetry at microdisc electrodes for a stepwise two electron reduction (A + 2e(-) reversible arrow B + e(-) reversible arrow C) where the relevant formal potentials of the A/B and B/C couples are such that two distinct voltammetric waves are seen. Simulations are used to explore quantitatively the effect of comproportionation (A + C -> 213) on the observed cyclic voltammetry and potential-step chronoamperometly. It is found that, in the limit of electrochemical reversibility, the presence of comproportionation can be discerned using cyclic voltammetry only at high scan-rates and when the diffusion coefficients of the species (D-A, D-B, and D-C) are significantly different, such that D-B/D-A > 1.5 and D-C/D-A > 1.5 or D-B/D-A < 0.75 and D-C/D-A < 0.75. The theory is used to provide clear evidence for diffusionally controlled comproportionation in the stepwise two electron reduction of para-quaterphenyl in the solvent THF.
引用
收藏
页码:16042 / 16050
页数:9
相关论文
共 35 条
[1]  
Andrieux C.P., 1970, J ELECTROANAL CHEM, V28, P339
[2]   Quantitative voltammetry of the reduction of methyl benzoate in THF reveals strong ion pairing of the radical anion with tetra-n-butyl cations [J].
Baron, Ronan ;
Kershaw, Neil M. ;
Donohoe, Timothy J. ;
Compton, Richard G. .
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, 2009, 22 (03) :247-253
[3]   Potential Step Chronoamperometry at Microdisc Electrodes: Effect of Finite Electrode Kinetics [J].
Belding, Stephen R. ;
Rogers, Emma I. ;
Compton, Richard G. .
JOURNAL OF PHYSICAL CHEMISTRY C, 2009, 113 (10) :4202-4207
[4]   ELECTROCHEMICAL STUDIES ON ANION COORDINATION CHEMISTRY - APPLICATION OF THE MOLAR-RATIO METHOD TO COMPETITIVE CYCLIC VOLTAMMETRY [J].
BIANCHI, A ;
DOMENECH, A ;
GARCIAESPANA, E ;
LUIS, SV .
ANALYTICAL CHEMISTRY, 1993, 65 (21) :3137-3142
[5]   EFFECTS OF INTERCONVERSION AND ELECTRON-TRANSFER ON VOLTAMMETRIC RESPONSES FOR 2-COMPONENT SYSTEMS WITH DIFFERING DIFFUSION-COEFFICIENTS [J].
BLAUCH, DN ;
ANSON, FC .
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 1991, 309 (1-2) :313-318
[6]   ELECTRONIC-STRUCTURE OF HIGHLY CONDUCTING POLY-(PARA-PHENYLENE) CHAINS - AN ABINITIO HARTREE-FOCK STUDY [J].
BREDAS, JL ;
THEMANS, B ;
ANDRE, JM .
PHYSICAL REVIEW B, 1982, 26 (10) :6000-6002
[7]  
Britz D., 2005, Digital simulation in electrochemistry, V3rd
[8]  
Compton RG., 2018, UNDERSTANDING VOLTAM, DOI [DOI 10.1142/Q0155, 10.1142/q0155, DOI 10.1142/6430]