Frontiers of Circularly Polarized Luminescence Chemistry of Isolated Small Organic Molecules

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 (glum) of SOMs, a measure of degree of chirality in CPL, is typically in a range of 10−3 to 10−5, 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.