Knowledge Bank

Solutions of chiral molecules in nematic liquid crystals give induced cholesteric phases. They show characteristic infrared rotatory dispersion with strong anomalies (amplitude of about 1000 degrees per mm), called Reflexion cotton Effect (RCE) and Absorption cotton Effect (ACE). Several aspects make this IR-ORD an interesting new chiroptical $method1$:\begin{enumerate}\item[(i)] the method depends on chiral properties different from those leading to other chiroptical phenomena;\item[(ii)] the necessary amount of sample is small;\item[(iii)] it can be measured experimentally simple.\end{enumerate} Examples are given for the following fields of application: Verification of chirality, discrimination between enantiomers, determination of optical purity, trace determination, information on absolute configuration.