Circular polarization spectroscopy of chiral molecules

The use of circularly polarized radiation to obtain new information about the structure of chiral molecules will be explored. This area of spectroscopy is known as optical activity. The classical forms of optical activity, typically measured in the visible and ultraviolet regions of the spectrum, are called optical rotatory dispersion (ORD) and electronic circular dichroism (CD). In recent years, new forms of optical activity have been developed and applied to the study of molecular structure. These include two forms of fluorescence optical activity and two forms of vibrational optical activity. The vibrational forms are called infrared vibrational circular dichroism (VCD) and vibrational Raman optical activity (ROA). The principles of optical activity will be explained and the application of optical activity to problems of chemical and biological significance will be discussed.