Molecular and Nano Sciences Laboratory, Department of Physics, Tsinghua University, Beijing 100084, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Dec;77(5):948-53. doi: 10.1016/j.saa.2010.08.026. Epub 2010 Aug 14.
The temporal bond polarizabilities of pyridine adsorbed on the Ag electrode under various applied voltages are obtained from their surface enhanced Raman intensities. In so doing, the delicate bond behaviors of pyridine molecule in the surface enhanced Raman process are well demonstrated, including the effects by the charge transfer and electromagnetic mechanisms. Furthermore, the adsorption effect is well reflected by the bond polarizabilities after relaxation as contrasted with the calculated bond electronic densities in the ground state. The work of pyridine liquid is also shown because its comparison with that under adsorption deepens our understanding of the Raman process. Though the method is semi-classical and simple as contrasted with those based on the quantum chemistry, it indeed offers us a very clear physical picture. This work demonstrates that this approach is quite universal for the Raman active systems even under adsorption as far as their Raman profiles are well measured.
通过测量吡啶在银电极上吸附时的表面增强拉曼散射强度，得到了不同外加电压下吡啶的瞬态极化率。在这一过程中，吡啶分子在表面增强拉曼过程中的精细键行为得到了很好的展示，包括电荷转移和电磁机制的影响。此外，通过与基态下计算得到的键电子密度进行对比，在弛豫后，吸附键的极化率可以很好地反映出吸附作用。与吡啶液体的工作相比，它加深了我们对拉曼过程的理解。虽然与基于量子化学的方法相比，这种方法是半经典和简单的，但它确实为我们提供了一个非常清晰的物理图像。这项工作表明，只要拉曼活性体系的拉曼谱得到很好的测量，这种方法对吸附状态下的拉曼活性体系也是非常通用的。
