Kinetics of electron transfer to attached redox centers on gold electrodes in nonaqueous electrolytes

Ravenscroft, Melissa S.; Finklea, Harry O.

doi:10.1021/j100065a047

Cited by 117 publications

(112 citation statements)

References 4 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…CpFeCpCO 2 (CH 2 )l 6 SH and CpFeCpCO 2 (CH 2 ) 18 SH were prepared by literature methods. 9 Alkanethiols (hexadecyl and octadecyl, Aldrich, > 97%), absolute ethanol 15 SH, then rinsed with ethanol and used without annealing in alkanethiol solution.…”

Section: Methodsmentioning

confidence: 99%

Cyclic Voltammetric Analysis of Ferrocene Alkanethiol Monolayer Electrode Kinetics Based on Marcus Theory

Tender¹,

Carter²,

Murray³

1994

Anal. Chem.

240

234

View full text Add to dashboard Cite

Theory for electrode kinetics of surface-immobilized monolayers in cyclic voltammetry is developed based on the Marcus free energy-rate relation. Numerical calculations show that when the applied overpotential exceeds ~30% of the reorganizational energy of the electrode reaction, voltammetry predicted from Marcus theory differs from that based on classical Butler-Volmer kinetics with regard to wave shape, peak currents and their dependence on potential sweep rate, and variation of peak potential with potential sweep rate. Estimates of the standard rate constant, A®, can be made from Epak data without exact knowledge of reorganizational energies.Examples are given of evaluating A® for monolayers of ferrocene alkanethiols chemisorbed on Au(lll) electrodes, when the monolayers are highly ordered, and kinetically monodisperse, and when they are somewhat disordered, and kinetically disperse on bulk gold electrodes at room and 150 K temperatures.Theory enabling measurement of heterogeneous electrontransfer rates from cyclic voltammetric oxidation-reduction peak potential separations, AEpeak, was presented some time ago by Nicholson and Shain1 for diffusing and by Laviron2 for diffusionless (i.e., surface bound) electrochemical systems. This methodology is appealing by its ease of application; standard electron-transfer rate constants (A°) result from analysis of the dependence of AE^v alues on potential sweep rate using numerically generated working curves1 or explicit expressions.2 These theoretical formulations are based on the Butler-Volmer3 free energy-rate relation, which in the context of modern electron-transfer theory due to Marcus,4 assumes that the applied potential (free energy, overpotential, = E -E°') is much smaller than the electrode reaction's reorganizational energy barrier ( ). This paper will describe the theoretical and experimental behavior of cyclic voltammetry of nondiffusing (immobilized) electrode reactants when is not negligible in comparison to , i.e., in or approaching what is commonly referred to as the Marcus inverted region.4•5 This contribution is made in the context of recent potential step experiments6•7 with electroactive, self-assembled monolayers in which the ratio / is not small. Cochemisorption of a mixture of the alkanethiols CH3(CH2)i5SH and CpFeCpC02(CH2),6SH

show abstract

Section: Methodsmentioning

confidence: 99%

Cyclic Voltammetric Analysis of Ferrocene Alkanethiol Monolayer Electrode Kinetics Based on Marcus Theory

Tender¹,

Carter²,

Murray³

1994

Anal. Chem.

240

234

View full text Add to dashboard Cite

show abstract

“…In nonaqueous electrolytes, the CV peak shapes become broader and more distorted; the change is reversible upon reimmersion in aqueous electrolytes. 162 CVs of attached metalloporphyrins are generally poorly defined unless the porphyrin ring is incorporated into a protein or protein fragment. Cytochrome c has been studied extensively.…”

Section: Attached Redox Centersmentioning

confidence: 99%

“…The l values are also in surprisingly good agreement with a simple theoretical equation based on the energy of a charged sphere in a dielectric continuum. 162,228 Table 3 lists selected l values obtained in aqueous electrolytes.…”

Section: Long-range Electron Transfermentioning

confidence: 99%

Self‐Assembled Monolayers on Electrodes

Finklea

2000

Encyclopedia of Analytical Chemistry

Self Cite

View full text Add to dashboard Cite

Alkanethiols and related molecules spontaneously adsorb from solution or vapor phase onto oxide‐free metals, especially gold, to form close‐packed oriented monolayers. The ease and flexibility of the self‐assembly process provides a convenient method for altering the properties of the metal as an electrode. The close‐packed hydrocarbon layer blocks access of most solution species to the electrode surface. Consequently, interfacial capacitances are markedly reduced and most electron‐transfer reactions are strongly inhibited. The monolayers also provide a foundation for attachment of additional molecules or molecular layers to electrodes. Self‐assembled monolayers (SAMs) on electrodes have been used in voltammetric methods to improve the analytical sensitivity and to impart greater selectivity towards specific analytes. Redox molecules have been anchored at fixed and controllable distances from the electrode surface, thereby permitting the study of electron‐transfer kinetics over long distances and at large driving forces. The ability of SAMs to inhibit metal corrosion and to promote better adhesion of electroactive polymers has been demonstrated.

show abstract

“…Creager et al discovered that changing the length of co-adsorbed alkanethiols or of the electrolyte leads to interfacial solvation and double-layer effects and results in variations of the formal potential and the peak shape [12][13]16]. Finklea and co-workers studied py[Ru(NH 3 ) 5 ] 2+ -terminated SAMs in a range of organic electrolytes; they observed a greater variation of electron transfer rate constants and a smaller reorganization energy in nonpolar solvents than in the aqueous phase [19]. Bard and coworkers applied scanning electrochemical microscopy (SECM) to measure electron transfer rates between the gold electrode and the redox species either covalently attached to the SAMs or diffusing in solution [20].…”

Section: Introductionmentioning

confidence: 99%

Homogenized redox behavior of electroactive self-assembled monolayers on gold in the organic phase

Lin

Xiang

Shao

et al. 2015

Electrochimica Acta

View full text Add to dashboard Cite

Kinetics of electron transfer to attached redox centers on gold electrodes in nonaqueous electrolytes

Cited by 117 publications

References 4 publications

Cyclic Voltammetric Analysis of Ferrocene Alkanethiol Monolayer Electrode Kinetics Based on Marcus Theory

Cyclic Voltammetric Analysis of Ferrocene Alkanethiol Monolayer Electrode Kinetics Based on Marcus Theory

Self‐Assembled Monolayers on Electrodes

Homogenized redox behavior of electroactive self-assembled monolayers on gold in the organic phase

Contact Info

Product

Resources

About