|
Type |
Oral Presentation |
Area |
Oral Presentation for Young Physical Chemists I |
Room No. |
Room 305+306 |
Time |
THU 09:30-09:39 |
Code |
PHYS1.O-4 |
Subject |
Highly efficient, mode-specific vibrational excitation of organic-molecules by plasmon-induced electrons |
Authors |
Hyun-Hang Shin, Zee Hwan Kim* Department of Chemistry, Seoul National University, Korea |
Abstract |
We observed abnormally intense anti-Stokes SERS peak of symmetric NO stretching (νNO) of 4-nitrobenzenethiol (NBT) molecules placed at plasmonic gaps. Corresponding effective vibrational temperatures are found to be 550 K. Such vibrational excitation occurs during the early stage of photo-reduction of NBT, whereas non-reactive aromatic thiols with similar structures (such as 4-mercaptobenzonitrle, 4-methylbenzenethiol) do not show any sign of vibrational excitation. This mode-spedific excitation is successfully reproduced by inelastic resonant scattering of electrons ejected from the metallic surface. The chemical specificity of the events and local field dependence of anti-Stokes νNO intensity strongly support our modelling also. Furthermore, wavelength dependence of the anti-Stokes νNO intensity indicates that the electron originates from the excitation of localized surface plasmons of nanostructures. |
E-mail |
sunabc86@nate.com |
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