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Probing Adsorption Configurations of Small Molecules on Surfaces by Single‐Molecule Tip‐Enhanced Raman Spectroscopy
Author(s) -
Zhang Yao,
Zhang Rui,
Jiang Song,
Zhang Yang,
Dong ZhenChao
Publication year - 2019
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201800861
Subject(s) - raman spectroscopy , molecule , adsorption , chemical physics , raman scattering , chemistry , spectroscopy , molecular physics , nanotechnology , materials science , optics , organic chemistry , physics , quantum mechanics
Determining the adsorption configurations of organic molecules on surfaces, especially for relatively small molecules, is a key issue for understanding the microscopic physical and chemical processes in surface science. In this work, we have applied low‐temperature ultrahigh‐vacuum tip‐enhanced Raman scattering (TERS) technique to distinguish the configurations of small 4,4′‐bipyridine (44BPY) molecules adsorbed on the Ag(111) surface. The observed Raman spectra exhibit notable differences in the spectral features which can be assigned to three different molecular orientations, each featuring a specific fingerprint pattern based on the TERS selection rule that determines the distribution of the relative intensities of different vibrational peaks. Furthermore, such a small molecule can in turn act as a local probe to provide information on the local electric field distribution at the tip apex. Our work showcases the capability of TERS technique for obtaining information on adsorption configurations of small molecules on surfaces down to the single‐molecule level, which is of fundamental importance for many applications in the fields of molecular science and surface chemistry.