Electrochemical TERS Elucidates Potential-Induced Molecular Reorientation of Adenine/Au(111).
Electrochemical TERS Elucidates Potential-Induced Molecular Reorientation of Adenine/Au(111).
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DOI：
10.1002/anie.201704460
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发表时间：
2017-08
影响因子：
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通讯作者：
Natalia Martín Sabanés;Tatsuhiko Ohto;D. Andrienko;Yuki Nagata;Katrin F. Domke
中科院分区：
文献类型：
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作者：
Natalia Martín Sabanés;Tatsuhiko Ohto;D. Andrienko;Yuki Nagata;Katrin F. Domke
电化学表面活性源于带电界面上分子的相互作用和几何排列。我们提出了一种新型电化学尖端增强拉曼光谱仪，它可以获取吸附在原子级平坦金电极上的不到 100 个非共振小分子的振动指纹，以研究它们的吸附几何形状和化学反应性随施加电位的变化。结合腺嘌呤/Au(111)的实验和模拟数据，我们得出结论，质子化的物理吸附腺嘌呤在低电势下采用倾斜方向，而在零电荷电势周围垂直吸附。电势的进一步增加诱导腺嘌呤去质子化并重新定向为平面构型。 EC-TERS 扩展到吸附物重新定向的研究，显着拓宽了这种先进的光谱电化学工具对各种电化学界面的纳米级表征的适用性。
Electrochemical surface activity arises from the interaction and geometric arrangement of molecules at electrified interfaces. We present a novel electrochemical tip-enhanced Raman spectroscope that can access the vibrational fingerprint of less than 100 small, non-resonant molecules adsorbed at atomically flat Au electrodes to study their adsorption geometry and chemical reactivity as a function of the applied potential. Combining experimental and simulation data for adenine/Au(111), we conclude that protonated physisorbed adenine adopts a tilted orientation at low potentials, whereas it is vertically adsorbed around the potential of zero charge. Further potential increase induces adenine deprotonation and reorientation to a planar configuration. The extension of EC-TERS to the study of adsorbate reorientation significantly broadens the applicability of this advanced spectroelectrochemical tool for the nanoscale characterization of a full range of electrochemical interfaces.