Chapter 1
Frontiers of Circularly Polarized
Luminescence Chemistry of Isolated Small
Organic Molecules
Tadashi Mori
Abstract Lately, circularly polarized luminescence (CPL), differential left- and
right-polarized emission from chiral materials, has been attracted great attention,
especially that of small organic molecules (SOMs). Despite the fact that the luminescence dissymmetry factor (g lum ) of SOMs, a measure of degree of chirality in
CPL, is typically in a range of 10
À3 to 10
À5 , considerably smaller than those based
on materials with forbidden transition, the value of SOM-based CPL materials are
progressively revised upwards. This trend is primarily due to the fact that a structural
modification of SOMs is permanently rational and relatively easy, allowing a
straightforward control of absorption and/or emission wavelengths as well as luminescence intensity. Biological compatibility and ease of device fabrication are
additional advantages of SOM-based CPL materials. In this chapter, we outline the
basics of CPL such as a definition and a quantification. Then, we briefly discuss
about an information attained by the CPL measurement of SOMs. Finally, a perspective on the rapid progress of SOM-based CPL materials is provided.
1.1 Introduction
In whole of the following chapters of this book, you will soon find the recent
advances of circularly polarized luminescence (CPL) behaviors of isolated small
organic molecules (SOMs) and some related phenomena. Before going into individual topic in details, we briefly outline in this first chapter the basic concept and
technical details of CPL. These include a definition of CPL, a quantification of CPL
intensity, and an information attained by the CPL measurement. This chapter may be
skipped for the specialists; however, we provide this fundamental information
focusing on for those who are relatively new to this field, to facilitate a further
reading. At the end of this chapter, a blight perspective on latest development of
T. Mori (*)
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita,
Japan
e-mail: tmori@chem.eng.osaka-u.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
T. Mori (ed.), Circularly Polarized Luminescence of Isolated Small Organic
Molecules, https://doi.org/10.1007/978-981-15-2309-0_1
1
Frontiers of Circularly Polarized
Luminescence Chemistry of Isolated Small
Organic Molecules
Tadashi Mori
Abstract Lately, circularly polarized luminescence (CPL), differential left- and
right-polarized emission from chiral materials, has been attracted great attention,
especially that of small organic molecules (SOMs). Despite the fact that the luminescence dissymmetry factor (g lum ) of SOMs, a measure of degree of chirality in
CPL, is typically in a range of 10
À3 to 10
À5 , considerably smaller than those based
on materials with forbidden transition, the value of SOM-based CPL materials are
progressively revised upwards. This trend is primarily due to the fact that a structural
modification of SOMs is permanently rational and relatively easy, allowing a
straightforward control of absorption and/or emission wavelengths as well as luminescence intensity. Biological compatibility and ease of device fabrication are
additional advantages of SOM-based CPL materials. In this chapter, we outline the
basics of CPL such as a definition and a quantification. Then, we briefly discuss
about an information attained by the CPL measurement of SOMs. Finally, a perspective on the rapid progress of SOM-based CPL materials is provided.
1.1 Introduction
In whole of the following chapters of this book, you will soon find the recent
advances of circularly polarized luminescence (CPL) behaviors of isolated small
organic molecules (SOMs) and some related phenomena. Before going into individual topic in details, we briefly outline in this first chapter the basic concept and
technical details of CPL. These include a definition of CPL, a quantification of CPL
intensity, and an information attained by the CPL measurement. This chapter may be
skipped for the specialists; however, we provide this fundamental information
focusing on for those who are relatively new to this field, to facilitate a further
reading. At the end of this chapter, a blight perspective on latest development of
T. Mori (*)
Department of Applied Chemistry, Graduate School of Engineering, Osaka University, Suita,
Japan
e-mail: tmori@chem.eng.osaka-u.ac.jp
© Springer Nature Singapore Pte Ltd. 2020
T. Mori (ed.), Circularly Polarized Luminescence of Isolated Small Organic
Molecules, https://doi.org/10.1007/978-981-15-2309-0_1
1