Optical Images of Molecular Vibronic Couplings from Tip-Enhanced Fluorescence Excitation SpectroscopyY Show others and affiliations
2022 (English) In: JACS Au, E-ISSN 2691-3704, Vol. 2, no 1, p. 150-158Article in journal (Refereed) Published
Abstract [en]
Tip-based photoemission spectroscopic techniques have now achieved subnanometer resolution that allows visualization of the chemical structure and even the ground-state vibrational modes of a single molecule. However, the ability to visualize the interplay between electronic and nuclear motions of excited states, i.e., vibronic couplings, is yet to be explored. Herein, we theoretically propose a new technique, namely, tip-enhanced fluorescence excitation (TEFE). TEFE takes advantage of the highly confined plasmonic field and thus can offer a possibility to directly visualize the vibronic effect of a single molecule in real space for arbitrary excited states in a given energy window. Numerical simulations for a single porphine molecule confirm that vibronic couplings originating from Herzberg-Teller (HT) active modes can be visually identified. TEFE further enables high-order vibrational transitions that are normally suppressed in the other plasmon-based processes. Images of the combination vibrational transitions have the same pattern as that of their parental HT active mode's fundamental transition, providing a direct protocol for measurements of the activity of Franck-Condon modes of selected excited states. These findings strongly suggest that TEFE is a powerful strategy to identify the involvement of molecular moieties in the complicated electron-nuclear interactions of the excited states at the single-molecule level.
Place, publisher, year, edition, pages American Chemical Society (ACS) , 2022. Vol. 2, no 1, p. 150-158
Keywords [en]
vibronic coupling, tip-enhanced fluorescence excitation, single-molecule imaging, plasmonic field, Franck-Condon activity
National Category
Theoretical Chemistry
Identifiers URN: urn:nbn:se:kth:diva-310791 DOI: 10.1021/jacsau.1c00442 ISI: 000772069200015 PubMedID: 35098231 Scopus ID: 2-s2.0-85134593877 OAI: oai:DiVA.org:kth-310791 DiVA, id: diva2:1650479
Note QC 20220407
2022-04-072022-04-072024-03-15 Bibliographically approved