Computational Investigation of the Important Factors in Surface-enhanced Raman Spectra Selection Rules
Paper ID : 1645-ICNS
Authors:
Zahra Jamshidi *
Chemistry Department, Sharif University of Technology
Abstract:
Ever since its discovery, Surface Enhanced Raman Spectroscopy (SERS) has become an efficient analytical tool due its highly sensitive detection and finger print characteristic. Amongst its main enhancement mechanisms, the charge transfer (CT) mechanism of SERS plays the main role in the pattern of the spectra which makes the determination of its selection rules the key to understanding the finger print characteristic of SERS. In this work we have studies different factors affecting the CT mechanism of SERS in order to better understand its selection rules. To do so, we have considered the effect of electrode potential, molecular symmetry and orientation, ligand-surface bond length and direction of the external field. We have employed the excited-state gradient and IMDHO approximations under the time-dependent resonance Raman theory to produce the CT-SERS spectra. Furthermore, we investigated different theoretical factors to explain the pattern of the spectra including the CDD maps, dimensionless displacements and other ground and excited-state features. Our results were successfully matched with the experiment and together with the investigation of the main theoretical factors, helped us better understand the CT-SERS selection rules.
Keywords:
“Surface Enhanced Raman Spectroscopy (SERS); Charge Transfer Mechanism (SERS); Selection Rules; Exited-State Gradient Approximation”
Status : Abstract Accepted (Poster Presentation)