Chiroptical properties: Origin and applications

This chapter presents a discussion on origin of optical activity. The concept of plane polarised light, circularly polarised light, circular birefringence, and circular dichroism has been illustrated with suitable figures and discussions. Theory related to the origin of optical activity has been provided. A discussion on Optical Rotatory Dispersion curves (ORD) and Circular Dichroism (CD) curves, along with Cotton Effect, has been provided with respective applications of the same. A discussion on optical activity displayed by symmetric chromophores perturbed by a chiral unit and optical activity displayed by inherently dissymmetric chromophores, exhibiting large optical rotations, has been provided. The sector rules, namely, the axial α-halo ketone rule and the Octant rule have been provided with applications of the same. Illustrations of various helicity rules for inherently chiral chromophores have been provided. The Exciton Coupling phenomena has been discussed with suitable illustration.