A DFT Approach to the Surface-Enhanced Raman Scattering of 4-Cyanopyridine Adsorbed on Silver Nanoparticles

A Surface-Enhanced Raman Scattering (SERS) spectrum of 4-cyanopyridine (4CNPy) was recorded on silver plasmonic nanoparticles and analyzed by using Density Functional Theory (DFT) calculations. Two simple molecular models of the metal−4CNPy surface complex with a single silver cation or wi...

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Bibliographic Details
Main Authors: Isabel López-Tocón, Samuel Valdivia, Juan Soto, Juan Carlos Otero, Francesco Muniz-Miranda, Maria Cristina Menziani, Maurizio Muniz-Miranda
Format: Article
Language:English
Published: MDPI AG 2019-08-01
Series:Nanomaterials
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Online Access:https://www.mdpi.com/2079-4991/9/9/1211
Description
Summary:A Surface-Enhanced Raman Scattering (SERS) spectrum of 4-cyanopyridine (4CNPy) was recorded on silver plasmonic nanoparticles and analyzed by using Density Functional Theory (DFT) calculations. Two simple molecular models of the metal&#8722;4CNPy surface complex with a single silver cation or with a neutral dimer (Ag<sup>+</sup>&#8722;4CNPy, Ag<sub>2</sub>&#8722;4CNPy), linked through the two possible interacting sites of 4CNPy (aromatic nitrogen, N, and nitrile group, CN), were considered. The calculated vibrational wavenumbers and intensities of the adsorbate and the isolated species are compared with the experimental Raman and SERS results. The analysis of the DFT predictions and the experimental data indicates that 4CNPy adsorbs preferentially on neutral/charged active sites of the silver nanoparticles through the nitrogen atom of the aromatic ring with a perpendicular orientation.
ISSN:2079-4991