A joint experimental and theoretical Raman study on the interactions of pyridine adsorbed on chemically pure Ag18 clusters. (24th June 2019)

• Record Type: Journal Article
• Authors: An, Pan; Wu, Haiming; Pembere, Anthony M.S.; Luo, Zhixun
• Is Part Of: Journal of Raman spectroscopy. Volume 50:Number 10(2019)
• Page Start: 1477
• Page End: 1484
• Publication Date: 2019-06-24
• Subjects: pyridine–Ag18 system -- Raman -- charge transfer -- calculation; Raman spectroscopy -- Periodicals; 535.846
• DOI: 10.1002/jrs.5653
• Languages: English
• ISSNs: 0377-0486

Abstract

Abstract: The interaction of pyridine–Ag has been a hot topic since the finding of surface‐enhanced Raman scattering; however, there is still challenge to accurately evaluate the interactions within nano‐systems. Here we have synthesized chemically pure Ag18 nanoclusters by a facile method based on laser ablation in liquid and conducted a joint experimental and theoretical Raman spectroscopic study for pyridine adsorbed on the specific‐sized Ag clusters. As a result, altered Raman feature for the pyridine‐Ag18 system in contrast to pure pyridine is observed shedding light on the charge‐transfer interactions between pyridine and Ag. Utilizing natural population analysis, we studied the charge distribution before and after pyridine adsorbed on the Ag18 cluster. Also, we calculated static polarizability components and isotropic polarizability of pyridine and the pyridine‐Ag18 complex and studied the donor‐acceptor orbital overlaps via natural bond orbital analysis, charge decomposition analysis, electron density difference analysis, and density of state analysis. Such a comprehensive and semiquantitative study provides firm evidence for the chemical mechanism in surface‐enhanced Raman scattering theory. Abstract : We have synthesized chemically pure Ag18 nanoclusters by a facile method based on laser ablation in water and conducted a joint experimental and theoretical Raman spectroscopic study of pyridine adsorbed on the Ag clusters. Comprehensive discussion involving static polarizability components, isotropic polarizability, natural bond orbital analysis, charge decomposition analysis, and density of state analysis, etc., is addressed, providing full information for the chemical mechanism in a surface‐enhanced Raman scattering‐like system free of electromagnetic enhancement.