Chapter 8
Other Topics
Abstract This chapter introduces some recent topics in the SFG spectroscopy,
particularly the χ (3) effect for the charged interfaces and the chiral applications
of SFG spectroscopy. The significance of χ (3) effect is now recognized in the SFG
and SHG spectra when interfaces are charged, such as the electrolyte interfaces
and charged solid-liquid interfaces. Understanding of this effect is indispensable to
analyze the spectra of these systems. Chiral application of the SFG spectroscopy has
been also advanced recently, though chiral systems are known to be SFG active for
long time. It could offer a new probe technique of chiral species at interfaces. The
present chapter discuss basic features of chiral applications, which are somewhat
different from the features of ordinary applications to interfaces.
Keywords χ (3) effect · Surface charge · Chiral SFG
Recent development of SFG spectroscopy has brought new areas of applications
as interface probe. Here we treat some recent topics in the SFG spectroscopy.
Section 8.1 deals with the “χ (3) effect”, which is pertinent to liquids in contact
to charged substrates, such as charged solid (membrane)-liquid interfaces and
electrode-solution interfaces. The χ (3) effect could have substantial contributions to
the SFG/SHG spectra from these charged interfaces. It becomes an additional source
of SFG/SHG, and could compete with the intrinsic signal from the interface. Precise
understanding of this effect is critical to interpret the SFG/SHG spectra of charged
interfaces. Section 8.2 treats chiral applications of SFG spectroscopy. The SFG is
allowed in chiral systems in principle, as the inversion symmetry is broken. Actually
the SFG as well as SHG from non-centrosymmetric materials is widely utilized in
optical conversion devices. However, applications of SFG as a spectroscopic tool of
probing chiral species have been relatively less explored. Recently the SFG/SHG
could be utilized as a chiral probe at interfaces. The present section summarizes
fundamental features of chiral SFG/SHG spectroscopy.
© Springer Nature Singapore Pte Ltd. 2018
A. Morita, Theory of Sum Frequency Generation Spectroscopy,
Lecture Notes in Chemistry 97, https://doi.org/10.1007/978-981-13-1607-4_8
201
Other Topics
Abstract This chapter introduces some recent topics in the SFG spectroscopy,
particularly the χ (3) effect for the charged interfaces and the chiral applications
of SFG spectroscopy. The significance of χ (3) effect is now recognized in the SFG
and SHG spectra when interfaces are charged, such as the electrolyte interfaces
and charged solid-liquid interfaces. Understanding of this effect is indispensable to
analyze the spectra of these systems. Chiral application of the SFG spectroscopy has
been also advanced recently, though chiral systems are known to be SFG active for
long time. It could offer a new probe technique of chiral species at interfaces. The
present chapter discuss basic features of chiral applications, which are somewhat
different from the features of ordinary applications to interfaces.
Keywords χ (3) effect · Surface charge · Chiral SFG
Recent development of SFG spectroscopy has brought new areas of applications
as interface probe. Here we treat some recent topics in the SFG spectroscopy.
Section 8.1 deals with the “χ (3) effect”, which is pertinent to liquids in contact
to charged substrates, such as charged solid (membrane)-liquid interfaces and
electrode-solution interfaces. The χ (3) effect could have substantial contributions to
the SFG/SHG spectra from these charged interfaces. It becomes an additional source
of SFG/SHG, and could compete with the intrinsic signal from the interface. Precise
understanding of this effect is critical to interpret the SFG/SHG spectra of charged
interfaces. Section 8.2 treats chiral applications of SFG spectroscopy. The SFG is
allowed in chiral systems in principle, as the inversion symmetry is broken. Actually
the SFG as well as SHG from non-centrosymmetric materials is widely utilized in
optical conversion devices. However, applications of SFG as a spectroscopic tool of
probing chiral species have been relatively less explored. Recently the SFG/SHG
could be utilized as a chiral probe at interfaces. The present section summarizes
fundamental features of chiral SFG/SHG spectroscopy.
© Springer Nature Singapore Pte Ltd. 2018
A. Morita, Theory of Sum Frequency Generation Spectroscopy,
Lecture Notes in Chemistry 97, https://doi.org/10.1007/978-981-13-1607-4_8
201