Environmental Effects on Redox Potentials of Viologen Groups Embedded in Electroactive Self-Assembled Monolayers.
Environmental Effects on Redox Potentials of Viologen Groups Embedded in Electroactive Self-Assembled Monolayers.
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DOI：
10.1021/la00046a023
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发表时间：
1992-10
期刊：
影响因子：
3.9
通讯作者：
H. Long;D. Buttry
中科院分区：
文献类型：
--
作者：
H. Long;D. Buttry
摘要：描述了一类能够形成电活性自组装单分子层的新型氧化还原表面活性剂的电化学行为。这些化合物具有源自著名的紫精的氧化还原部分，其显示出两个不同的、可逆的单电子偶合。它们良好的电化学性质使其被用于各种研究，从电子转移介导到氧化还原蛋白质，从电极表面吸附的表面增强拉曼研究到电极表面超分子组装体的行为。我们对理解离子相互作用和溶剂化过程对此类超分子组装体中氧化还原行为的影响感兴趣，这促使我们合成了其中几种化合物，并使用电化学（循环伏安法，CV）和石英晶体微天平（EQCM）技术研究它们在此类组装体中的氧化还原行为。在本报告中，我们描述了紫精部分的氧化还原电位对其在组装体中确切位置（即相对于单分子层/电极和单分子层/溶液界面）的强烈依赖性，并进一步阐述了我们之前关于电化学行为对单分子层组装体中存在的阴离子类型的依赖性的报告。
Abstract : The electrochemical behavior of a new class of redox surfactant capable of forming electroactive, self-assembled monolayers was described. These compounds have redox moieties derived from the well known viologens, which display two distinct, reversible, one-electron couples. Their well behaved electrochemistry has lead to their use in a variety of studies ranging from electron transfer mediation to redox proteins to surface enhanced Raman studies of adsorption at electrode surfaces to the behavior of supermolecular assemblies at electrode surfaces. Our interest in understanding the influence of ionic interactions and solvation processes on redox behavior in such supermolecular assemblies lead us to synthesize several of these compounds and study their redox behavior in such assemblies using both electrochemical (cyclic voltametric, CV) and quartz crystal microbalance (EQCM) techniques. In this report we describe the strong dependence of the redox potential of the viologen moiety on its exact position within the assembly (i.e. with respect to the monolayer/electrode and monolayer/solution interfaces) and expand on our previous report of the dependence of electrochemical behavior on the type of anion present within the monolayer assembly.