Observation of the Turnover between the Solvent Friction (Overdamped) and Tunneling (Nonadiabatic) Charge-Transfer Mechanisms for a Au/Fe(CN)63-/4- Electrode Process and Evidence for a Freezing Out of the Marcus Barrier
Observation of the Turnover between the Solvent Friction (Overdamped) and Tunneling (Nonadiabatic) Charge-Transfer Mechanisms for a Au/Fe(CN)63-/4- Electrode Process and Evidence for a Freezing Out of the Marcus Barrier
复制标题
Au/Fe(CN)63-/4- 电极过程中溶剂摩擦（过阻尼）和隧道（非绝热）电荷转移机制之间转换的观察以及马库斯势垒冻结的证据
DOI：
10.1021/jp0041095
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发表时间：
2001
影响因子：
2.9
通讯作者：
D. Waldeck
中科院分区：
文献类型：
--
作者：
†‡ and Dimitri E. Khoshtariya;T. Dolidze;and Leonid D. Zusman;D. Waldeck
在Au/Fe（CN）63-/4-氧化还原体系中，通过改变电子耦合强度，观察到了溶剂控制区（电子转移速率常数取决于溶剂摩擦）和非绝热电子转移极限之间的转变.溶剂摩擦制度被证明为裸Au电极的表观标准速率常数是在含有1 M KCl的水/葡萄糖溶液的粘度成反比。通过制备不同厚度的正烷基乙醇胺涂覆的金电极（Au-S-（CH 2）n-1-CH 3，其中n = 2，4，6，8）来降低Au和氧化还原物种之间的电子耦合的幅度。对于Au电极的情况下，涂层由乙烷乙烷单分子层（n = 2）的速率常数表现出分数粘度依赖性，而电极与n = 4，6，和8亚甲基在膜中没有表现出粘度依赖性。这一趋势表明，两种制度之间的总体更替正在逐步进行。在...
By variation of the electronic coupling strength, the transition between the solvent-controlled regime (in which the electron-transfer rate constant depends on the solvent friction) and the nonadiabatic electron-transfer limit was observed for the Au/Fe(CN)63-/4- redox system. The solvent friction regime was demonstrated for a bare Au electrode by showing that the apparent standard rate constant was inversely proportional to the viscosity in water/glucose solutions containing 1 M KCl. The magnitude of the electronic coupling between the Au and the redox species was reduced by preparing n-alkanethiol-coated gold electrodes (Au−S−(CH2)n-1−CH3 with n = 2, 4, 6, 8) of different thicknesses. For the case of a Au electrode coated by an ethanethiol monolayer (n = 2) the rate constant exhibited a fractional viscosity dependence, whereas the electrodes with n = 4, 6, and 8 methylenes in the film showed no viscosity dependence. This trend is indicative of an overall gradual turnover between the two regimes. In the ...