Chapter 8
Modulations of Electronic States
in Plasmonic Strong Coupling Systems
and Their Application to Photochemical
Reaction Fields
Kosei Ueno
Abstract The modulation of electronic or transition states plays an important role
in improving the selectivity and reactivity of chemical reactions. In recent years,
the strong coupling between an optical mode and excitons or molecular vibrational
modes has received attractive attention as a physical phenomenon for controlling
the activation energy of chemical reactions by modulating the electronic state or
the vibrational state. In this study, we investigated the spectral properties of hybrid
states formed by the strong coupling between plasmon and molecular/intermolecular
vibrational modes in the infrared wavelength region. The strong coupling between
plasmon and molecular excitonic states have been also studied for demonstrating how
to confirm the formation of hybrid states. We developed a highly efficient photochemical reaction field by using modal strong coupling systems between plasmons and
different optical modes.
Keywords Strong coupling · Modulation of electronic states · Infrared localized
surface plasmon · Modal strong coupling
8.1 Introduction
Strong coupling has received considerable attention as a physical phenomenon modulating molecular electronic states based on quantum mechanical interactions with
optical modes such as microcavity, plasmon, and so on [1, 2]. If the electronic
state is modulated by the strong coupling, it is expected to change the reactivity
of molecules. Therefore, strong coupling works as a catalyst for promoting photochemical reactions. On this basis, we have explored strong coupling between localized surface plasmon resonance (LSPR) and molecular excitonic states by using
J-aggregate of molecules having a relatively larger dipole moment [3, 4]. Ebbesen
and co-workers recently demonstrated the strong coupling between microcavity and
K. Ueno (B)
Department of Chemistry, Faculty of Science, Hokkaido University, Kita-Ku,
Sapporo, Hokkaido 060-0810, Japan
e-mail: ueno@sci.hokudai.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_8
135
Modulations of Electronic States
in Plasmonic Strong Coupling Systems
and Their Application to Photochemical
Reaction Fields
Kosei Ueno
Abstract The modulation of electronic or transition states plays an important role
in improving the selectivity and reactivity of chemical reactions. In recent years,
the strong coupling between an optical mode and excitons or molecular vibrational
modes has received attractive attention as a physical phenomenon for controlling
the activation energy of chemical reactions by modulating the electronic state or
the vibrational state. In this study, we investigated the spectral properties of hybrid
states formed by the strong coupling between plasmon and molecular/intermolecular
vibrational modes in the infrared wavelength region. The strong coupling between
plasmon and molecular excitonic states have been also studied for demonstrating how
to confirm the formation of hybrid states. We developed a highly efficient photochemical reaction field by using modal strong coupling systems between plasmons and
different optical modes.
Keywords Strong coupling · Modulation of electronic states · Infrared localized
surface plasmon · Modal strong coupling
8.1 Introduction
Strong coupling has received considerable attention as a physical phenomenon modulating molecular electronic states based on quantum mechanical interactions with
optical modes such as microcavity, plasmon, and so on [1, 2]. If the electronic
state is modulated by the strong coupling, it is expected to change the reactivity
of molecules. Therefore, strong coupling works as a catalyst for promoting photochemical reactions. On this basis, we have explored strong coupling between localized surface plasmon resonance (LSPR) and molecular excitonic states by using
J-aggregate of molecules having a relatively larger dipole moment [3, 4]. Ebbesen
and co-workers recently demonstrated the strong coupling between microcavity and
K. Ueno (B)
Department of Chemistry, Faculty of Science, Hokkaido University, Kita-Ku,
Sapporo, Hokkaido 060-0810, Japan
e-mail: ueno@sci.hokudai.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
H. Miyasaka et al. (eds.), Photosynergetic Responses in Molecules
and Molecular Aggregates, https://doi.org/10.1007/978-981-15-5451-3_8
135