Discrimination of Enantiomers at Microgram Level Using Liquid Crystalline Solutions

Abstract

In a nematic liquid crystal a cholesteric, i.e., helical, arrangement of molecules is induced by doping with a low concentration of chiral molecules. This structure is oppositely coiled for enantiomers leading to countercurrent infrared rotatory dispersion curves. It is shown that by employing this effect, enantiomers can be discriminated even if only microgram quantities are available. The measurement of the rotatory dispersion using a normal infrared spectrometer is described, and examples to demonstrate the applicability are given.