Toyonobu Usuki

Abstract Circular dichroism (CD) spectroscopy has been a powerful technique in the structural analysis of various chiral supramolecular systems. In order to obtain correct structural information it is essential to understand the basic concepts of CD, to optimize the measurement condition, and to properly interpret the data. This chapter addresses the following topics in order for the readers to use CD spectroscopy more efficiently: (i) the fundamental principles of CD spectroscopy and the technical point of the measurements; (ii) the exciton chirality method and its use in the configurational and conformational analysis of supermolecules; (iii) the introduction of basic concepts of induced CD; and (iv) the recent developments of computational simulation of CD spectra. We show that these basic concepts are applicable to the interpretation of CD data of further complicated supramolecular systems, by showing examples of a broad range of chiral supermolecules such as host‐guest systems, mechanically interlocked molecules, molecular machines, foldamer, polymers, and self‐assembled molecules. This chapter also briefly introduces the applications of a newly emerged CD (vibrational circular dichroism (VCD) spectroscopy) to supermolecules.