Loading...

Role of herzberg-teller vibronic coupling in surface-enhanced resonance raman spectra of 4,4′-diaminotolane with nearly close molecular and charge-transfer transitions

Jamshidi, Z ; Sharif University of Technology | 2021

231 Viewed
  1. Type of Document: Article
  2. DOI: 10.1021/acs.jpcc.1c04524
  3. Publisher: American Chemical Society , 2021
  4. Abstract:
  5. We have investigated the surface-enhanced resonance Raman spectroscopy (SERRS) for 4,4′-diaminotolane absorbed on silver experimentally and theoretically. Experimental observation shows greatly enhanced bg symmetric modes ν26 and ν27, which are silent in normal Raman spectroscopy and SERS on gold. The dependence of the surface-enhanced Raman spectroscopy (SERS) spectra on five excitation lines has also been registered and classified for single bands into three profiles referring to the different contributions of resonant transitions. Theoretical calculations based on the time-dependent path integral formalism by including the Herzberg-Teller correction reproduce the experimental spectra with good agreement. The importance of the Herzberg-Teller term to improve the pattern of the spectra and the enhancement of totally and non-totally symmetric modes are recognized and elucidated. The strong charge-transfer transition with nearly close molecular excitations in this compound creates an opportunity to obtain insight into the combination of molecular and charge-transfer transitions and their effect on the chemical mechanism of SERS. © 2021 American Chemical Society
  6. Keywords:
  7. Gold metallography ; Raman spectroscopy ; Silver metallography ; Charge transfer transitions ; Experimental spectra ; Molecular excitations ; Normal raman spectroscopies ; Surface enhanced Raman spectroscopy ; Surface enhanced resonance ; Surface-enhanced resonance raman spectroscopies ; Theoretical calculations ; Charge transfer ; Charge-Transfer Transitions
  8. Source: Journal of Physical Chemistry C ; Volume 125, Issue 31 , 2021 , Pages 17202-17211 ; 19327447 (ISSN)
  9. URL: https://pubs.acs.org/doi/10.1021/acs.jpcc.1c04524