Face-Dependent Shell-Isolated Nanoparticle Enhanced Raman Spectroscopy of 2,2′-Bipyridine on Au(100) and Au(111)
Face-Dependent Shell-Isolated Nanoparticle Enhanced Raman Spectroscopy of 2,2′-Bipyridine on Au(100) and Au(111)
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DOI：
10.1021/jp211884s
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发表时间：
2012-03-01
影响因子：
3.7
通讯作者：
Gewirth, Andrew A.
中科院分区：
文献类型：
--
作者：
Butcher, Dennis P., Jr.;Boulos, Stefano P.;Gewirth, Andrew A.
我们使用新开发的壳隔离纳米颗粒增强拉曼光谱 (SHINERS) 技术研究了 Au(100) 和 Au(111) 表面上 2,2'-联吡啶分子的电势依赖性组装。我们展示了在阳极和阴极极化下收集的吸附在两个表面上的 2,2'-联吡啶的电位依赖性 SHINERS 光谱。通过微扰相关移动窗二维光谱（PCMVV2D）和二维相关光谱（2DCOS）对数据集进行分析来表征一系列过程。获得了精致的光谱细节，并允许对复杂的环呼吸模式和 C-C 环间拉伸模式进行表征，这些模式可诊断表面上的分子取向。 SHINERS 还可以检测多个被遮挡的振动峰值。分析表明，在非常负的电位下，2,2'-联吡啶以无序、混合状态吸附，具有 pi 平面顺式和几种不同的垂直 N 结合顺式方向，与之前发表的报告相反。我们的研究结果提供了对 Au 单晶上 2,2'-联吡啶吸附的深入了解，并将 SHINERS 与二维相关分析有力地结合起来，以产生更详细的光谱跃迁视图。
We have investigated the potential-dependent assembly of 2,2'-bipyridine molecules on both Au(100) and Au(111) surfaces using a newly developed Shell-Isolated Nanoparticle Enhanced-Raman Spectroscopy (SHINERS) technique. We present potential-dependent SHINERS spectra of 2,2'-bipyridine adsorbed on both surfaces collected under anodic as well as cathodic polarization. A series of processes were characterized by the analysis of the data set with Perturbation Correlation Moving Window Two-Dimensional Spectroscopy (PCMVV2D) and Two-Dimensional Correlation Spectroscopy (2DCOS). Exquisite spectral detail was achieved and allowed for the characterization of the complicated ring breathing mode and C-C inter-ring stretching modes that are diagnostic of molecular orientation on the surfaces. Detection of several occluded vibration peaks was also made possible with SHINERS. Analysis reveals that in very negative potentials 2,2'-bipyridine adsorbs in a disordered, mixed state with both pi-flat cis and several different vertically N-bound cis orientations, in contrast to previously published reports. Our findings provide insight into 2,2'-bipyridine adsorption on Au single crystals and also powerfully combine SHINERS with two-dimensional correlation analysis to yield a more detailed view of spectral transitions.