Conformational Contrast of Surface-Mediated Molecular Switches Yields Ångstrom-Scale Spatial Resolution in Ultrahigh Vacuum Tip-Enhanced Raman Spectroscopy
| Autor: | Eric A. Pozzi, Xing Chen, Richard P. Van Duyne, Mark C. Hersam, Xu Chen, Naihao Chiang, Lasse Jensen, Guillaume Goubert, Tamar Seideman, Dhabih V. Chulhai, Nan Jiang |
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| Rok vydání: | 2016 |
| Předmět: |
Molecular switch
Mechanical Engineering Analytical chemistry Bioengineering 02 engineering and technology General Chemistry 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Porphyrin 0104 chemical sciences symbols.namesake chemistry.chemical_compound Scanning probe microscopy Adsorption chemistry Metastability symbols Molecule General Materials Science 0210 nano-technology Raman spectroscopy Conformational isomerism |
| Zdroj: | Nano Letters. 16:7774-7778 |
| ISSN: | 1530-6992 1530-6984 |
| DOI: | 10.1021/acs.nanolett.6b03958 |
| Popis: | Tip-enhanced Raman spectroscopy (TERS) combines the ability of scanning probe microscopy (SPM) to resolve atomic-scale surface features with the single-molecule chemical sensitivity of surface-enhanced Raman spectroscopy (SERS). Here, we report additional insights into the nature of the conformational dynamics of a free-base porphyrin at room temperature adsorbed on a metal surface. We have interrogated the conformational switch between two metastable surface-mediated isomers of meso-tetrakis(3,5-ditertiarybutylphenyl)-porphyrin (H2TBPP) on a Cu(111) surface. At room temperature, the barrier between the porphyrin ring buckled up/down conformations of the H2TBPP-Cu(111) system is easily overcome, and a 2.6 A lateral resolution by simultaneous TERS and STM analysis is achieved under ultrahigh vacuum (UHV) conditions. This work demonstrates the first UHV-TERS on Cu(111) and shows TERS can unambiguously distinguish the conformational differences between neighboring molecules with Angstrom-scale spatial resolu... |
| Databáze: | OpenAIRE |
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