Doctor of Science, University of Science and Technology of China (2023)
Bachelor of Science, Anhui University (2017)
B.S., Anhui University, Materials Physics (2017)
Ph.D., University of Science and Technology of China, Physical Chemistry (2023)
Andrew Mannix, Postdoctoral Faculty Sponsor
Revealing Intramolecular Isotope Effects with Chemical-Bond Precision.
Journal of the American Chemical Society
Isotope substitution of a molecule not only changes its vibrational frequencies but also changes its vibrational distributions in real-space. Quantitatively measuring the isotope effects inside a polyatomic molecule requires both energy and spatial resolutions at the single-bond level, which has been a long-lasting challenge in macroscopic techniques. By achieving ångström resolution in tip-enhanced Raman spectroscopy (TERS), we record the corresponding local vibrational modes of pentacene and its fully deuterated form, enabling us to identify and measure the isotope effect of each vibrational mode. The measured frequency ratio νH/νD varies from 1.02 to 1.33 in different vibrational modes, indicating different isotopic contributions of H/D atoms, which can be distinguished from TERS maps in real-space and well described by the potential energy distribution simulations. Our study demonstrates that TERS can serve as a non-destructive and highly sensitive methodology for isotope detection and recognition with chemical-bond precision.
View details for DOI 10.1021/jacs.3c02728
View details for PubMedID 37338304
Determining structural and chemical heterogeneities of surface species at the single-bond limit
2021; 371 (6531): 818-+
The structure determination of surface species has long been a challenge because of their rich chemical heterogeneities. Modern tip-based microscopic techniques can resolve heterogeneities from their distinct electronic, geometric, and vibrational properties at the single-molecule level but with limited interpretation from each. Here, we combined scanning tunneling microscopy (STM), noncontact atomic force microscopy (AFM), and tip-enhanced Raman scattering (TERS) to characterize an assumed inactive system, pentacene on the Ag(110) surface. This enabled us to unambiguously correlate the structural and chemical heterogeneities of three pentacene-derivative species through specific carbon-hydrogen bond breaking. The joint STM-AFM-TERS strategy provides a comprehensive solution for determining chemical structures that are widely present in surface catalysis, on-surface synthesis, and two-dimensional materials.
View details for DOI 10.1126/science.abd1827
View details for Web of Science ID 000619664700051
View details for PubMedID 33602852