Electrochemical Write and Read Functionality through Oxidative Dimerization of Spiropyran Self-Assembled Mono layers on Gold
Electrochemical Write and Read Functionality through Oxidative Dimerization of Spiropyran Self-Assembled Mono layers on Gold
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DOI：
10.1021/jp406458a
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发表时间：
2013-09-12
影响因子：
3.7
通讯作者：
Browne, Wesley R.
中科院分区：
文献类型：
--
作者：
Ivashenko, Oleksii;van Herpt, Jochem T.;Browne, Wesley R.
与光致变色相反，自组装单层螺吡喃的电化学近年来只引起了适度的关注。在这篇文章中，描述了在多晶金表面上制备的 6-硝基-BIPS 螺吡喃 (SP) 自组装单层 (SAM) 的电化学氧化。通过循环伏安法、X射线光电子能谱 (XPS)、表面增强拉曼散射 (SERS) 和紫外/可见光吸收光谱电化学对 SAM 进行了表征。螺吡喃在溶液中的电化学氧化导致吲哚单元的芳基C-C偶联，从而形成对称螺吡喃二聚体。将溶液中电化学氧化螺吡喃二聚体获得的光谱数据与单分子层数据进行比较，证实金上的 SAM 中也发生类似的氧化偶联。形成的二聚体可以电化学氧化为单阳离子和双阳离子状态，并且在所有三种氧化还原状态下在特高压和环境条件下均表现出非常好的稳定性。此外，二聚螺吡喃自组装单分子层表现出光致变色现象，并通过XPS和SERS光谱进行了表征。
In contrast to their photochromism, the electrochemistry of spiropyrans in self-assembled monolayers has attracted only modest attention in recent years. In this contribution the electrochemical oxidation of self-assembled monolayers (SAMs) of 6-nitro-BIPS spiropyran (SP) prepared on polycrystalline gold surfaces is described. The SAMs were characterized with cyclic voltammetry, X-ray photoelectron spectroscopy (XPS), surface-enhanced Raman scattering (SERS), and UV/vis absorption spectroelectrochemistry. The electrochemical oxidation of spiropyrans in solution results in aryl C-C coupling of the indole units and thereby the formation of a symmetric spiropyran dimer. Comparison of spectroscopic data obtained for electrochemically oxidized spiropyran dimers in solution with data from monolayers confirms that a similar oxidative coupling occurs in the SAMs on gold also. The dimer formed can be oxidized electrochemically to monocationic and dicationic states and shows remarkably good stability in UHV and ambient conditions in all three redox states. In addition, the dimerized spiropyran self-assembled monolayer show photochromism, which was characterized by XPS and SERS spectroscopy.