Study of Multicenter Redox Molecules with Square Wave Voltammetry
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- 作者：Angela Molina ; Marié ; n M. Moreno ; Carmen Serna ; Manuela Ló ; pez-Tené ; s ; Joaquí ; n Gonzá ; lez ; Nuria Abenza
- 刊名：Journal of Physical Chemistry C
- 出版年：2007
- 出版时间：August 23, 2007
- 年：2007
- 卷：111
- 期：33
- 页码：12446 - 12453
- 全文大小：158K
- 年卷期：v.111,no.33(August 23, 2007)
- ISSN：1932-7455
文摘
An analytical explicit expression for the current obtained with the well-known multipulse technique squarewave voltammetry (SWV), corresponding to the reversible reduction/oxidation of multicenter redox moleculeswhose centers may or may not interact, has been given in Appendix. This equation is valid for sphericalelectrodes of any size, including planar electrodes (r0 
) and ultramicroelectrodes (r0 0) as limit cases,and it also permits us to deduce the behavior of these processes at the limit situations corresponding to smalland great square wave amplitudes. For the sake of simplicity, we have analyzed the behavior of bicentermolecules, ranging from noninteracting centers, for which the square wave current obtained is twice thatcorresponding to a single E mechanism, to strongly interacting centers which present two successive andwell-separated signals of one electron each. The results obtained here are easily extendable to molecules withany number of redox centers. The theoretical predictions have been tested with two experimental systems,quinizarine in acetonitrile and pyrazine in aqueous acid media, and an excellent agreement between theoryand experiments is found.
) and ultramicroelectrodes (r0 0) as limit cases,and it also permits us to deduce the behavior of these processes at the limit situations corresponding to smalland great square wave amplitudes. For the sake of simplicity, we have analyzed the behavior of bicentermolecules, ranging from noninteracting centers, for which the square wave current obtained is twice thatcorresponding to a single E mechanism, to strongly interacting centers which present two successive andwell-separated signals of one electron each. The results obtained here are easily extendable to molecules withany number of redox centers. The theoretical predictions have been tested with two experimental systems,quinizarine in acetonitrile and pyrazine in aqueous acid media, and an excellent agreement between theoryand experiments is found.