@Article{JAMS-8-70,
author = {Wang , JiyuWang , JingMa , CaiqingZhang , MeixiaDing , YongSong , Peng and Ma , Fengcai},
title = {The Mechanism Research for the Surface Plasmon-Catalysed Reaction of the Mercapto Group Substituted Benzoic Acid},
journal = {Journal of Atomic and Molecular Sciences},
year = {2017},
volume = {8},
number = {2},
pages = {70--74},
abstract = {<p style="text-align: justify;">In this study, we experimentally investigated the substituent effect on benzoic acid where the mercapto group was 
located in different positions, namely as 2-mercaptobenzoic acid (2-MBA), 3-mercaptobenzoic acid (3-MBA) and 
4-mercaptobenzoic acid (4-MBA). The substituent effect was found to have an influence on the surface 
plasmon-catalysed reaction on the surface of the Ag4 atoms in the reaction of MBA with silver sol. In addition to 
the direct evidence from the surface-enhanced Raman scattering (SERS), the chemical enhancement mechanism for the 
generation of the MBA-Ag complex is presented. In contrast with the normal Raman scattering (NRS) spectra, new 
signals appeared in the SERS spectra of 2-MBA, 3-MBA and 4-MBA under the theoretical and experimental conditions. 
On investigation of the SERS spectra, the characteristic peaks of the C ≡ C bond have been demonstrated. The 
structural, atomic and chemical bond properties of the three types of MBAs indicate that the S atom of the mercapto 
group in the MBA molecules is the position site that attaches to the silver substrate through the bond of S…Ag, 
and under laser irradiation, “hot electrons ” &nbsp;are generated between the surface of MBA and Ag4 atoms. With the effect 
of “hot electrons ” , the -COOH bond of the MBA molecules is broken, and then the two single carboxylate MBA molecules 
become dimerized thiophenol acetylene (TPA). To briefly consider the substituent effect, the SERS spectra of these 
three types of MBAs were specifically studied for the enhancement of the Raman signal intensity with a variational 
tendency evident. Therefore, the conclusion was reached that the substituent effect plays a vital role in the 
surface plasmon-catalysed reaction, where the changing of the surface-enhanced Raman intensity was demonstrated.</p>},
issn = {2079-7346},
doi = {https://doi.org/10.4208/jams.071617.090517a},
url = {http://global-sci.org/intro/article_detail/jams/10573.html}
}