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Volumn 13, Issue 16, 2007, Pages 4386-4395

Electron transfer and structural change: Distinguishing concerted and two-step processes

Author keywords

Conformational change; Electron transfer; Electron transfer kinetics; Isomerization

Indexed keywords

CONFORMATIONS; ISOMERIZATION; REACTION KINETICS; VOLTAMMETRY;

EID: 34250369926     PISSN: 09476539     EISSN: 15213765     Source Type: Journal    
DOI: 10.1002/chem.200700338     Document Type: Article
Times cited : (17)

References (26)
  • 1
    • 34250359971 scopus 로고    scopus 로고
    • A comment is in order about what is meant by a concerted electron transfer and structural change. Due to Franck-Condon restrictions, such a reaction cannot involve simultaneous transfer of the electron and changes in the nuclear coordinates. Rather, the concerted reaction involves reorganization of the reactant and solvent to a transition state configuration between reactant and product states with rapid electron transfer occurring at this point followed by further changes in nuclear configuration to reach the solvated product structure
    • A comment is in order about what is meant by a concerted electron transfer and structural change. Due to Franck-Condon restrictions, such a reaction cannot involve simultaneous transfer of the electron and changes in the nuclear coordinates. Rather, the concerted reaction involves reorganization of the reactant and solvent to a transition state configuration between reactant and product states with rapid electron transfer occurring at this point followed by further changes in nuclear configuration to reach the solvated product structure.
  • 2
    • 34250346611 scopus 로고    scopus 로고
    • J. M. Hale in Reactions of Molecules at Electrodes (Ed.: N. S. Hush), Wiley, New York, 1971. pp. 229-257.
    • J. M. Hale in Reactions of Molecules at Electrodes (Ed.: N. S. Hush), Wiley, New York, 1971. pp. 229-257.
  • 12
    • 1042281128 scopus 로고    scopus 로고
    • Somewhat unexpectedly, for both the neutral and radical anion of α-nitrostilbene, it is the isomer with the two phenyl groups cis to one another that is the more stable form: C. Kraiya, P. Singh, Z. V. Todres, D. H. Evans, J. Electroanal. Chem. 2004, 563, 171-180.
    • Somewhat unexpectedly, for both the neutral and radical anion of α-nitrostilbene, it is the isomer with the two phenyl groups cis to one another that is the more stable form: C. Kraiya, P. Singh, Z. V. Todres, D. H. Evans, J. Electroanal. Chem. 2004, 563, 171-180.
  • 15
    • 34250380751 scopus 로고    scopus 로고
    • In the technique of cyclic voltammetry, a stationary working electrode is placed in a solution containing a high concentration of supporting electrolyte (to conduct charge through solution) and a low concentration (of the order of millimolar) of electroactive reactant. The solution is purged of dissolved air and is allowed to become quiescent. Then, the potential of the working electrode (with respect to a reference electrode) is caused to change linearly with time until a convenient switching potential is reached after which the direction of potential scan is reversed and the potential is returned (typically) to its initial value. The information content is in the resulting current-potential curve that is called a voltammogram. The principal experimental variables are the rate of change of potential scan rate, substrate concentration, and temperature. For a discussion of the principles of the method, see reference [16a
    • In the technique of cyclic voltammetry, a stationary working electrode is placed in a solution containing a high concentration of supporting electrolyte (to conduct charge through solution) and a low concentration (of the order of millimolar) of electroactive reactant. The solution is purged of dissolved air and is allowed to become quiescent. Then, the potential of the working electrode (with respect to a reference electrode) is caused to change linearly with time until a convenient switching potential is reached after which the direction of potential scan is reversed and the potential is returned (typically) to its initial value. The information content is in the resulting current-potential curve that is called a voltammogram. The principal experimental variables are the rate of change of potential (scan rate), substrate concentration, and temperature. For a discussion of the principles of the method, see reference [16a].
  • 19
    • 34250335774 scopus 로고    scopus 로고
    • As pointed out elsewhere,[18] the fact that the reaction pathway for reduction (A, e-=A, A, B, ) differs from the pathway for oxidation (B, B, e, A=B) might appear to be a violation of the principle of microscopic reversibility. However, the electrons involved in the reduction (near -1.7V; Figure 1) are from different energy states in the electrode than those involved in the oxidation (near -1.0 V) so the forward and reverse reactions are fundamentally different. Therefore, there is no violation of microscopic reversibility. In fact, the reduction and oxidation reactions could follow exactly opposite pathways A, e-A, A, B, and B, A, A, A, e, so long as the kinetics of the A, B. reaction are sufficiently facile. By the same token, as is about to be discussed, the reduction reac
    • .-=B + c: B -A. depending again on the kinetics of the chemical step. A-B.
  • 26
    • 33645529114 scopus 로고    scopus 로고
    • For a recent example of potential inversion and extensive references, see
    • For a recent example of potential inversion and extensive references, see N. A. Macías-Ruvalcaba, D. H. Evans, J. Phys. Chem. B 2006, 110, 5155-5160.
    • (2006) J. Phys. Chem. B , vol.110 , pp. 5155-5160
    • Macías-Ruvalcaba, N.A.1    Evans, D.H.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.