Enantiomeric excess measurements in weakly oriented chiral liquid crystal solvents through 2D 1H selective refocusing experiments

In this article, a simple and robust method is proposed for simplifying the analysis of proton spectra of molecules dissolved in weakly oriented chiral media. The NMR approach investigated is based on the use of proton selective refocusing 2D experiments (SERF) to measure proton-proton dipolar couplings from unresolved lines. This technique is applied to the case of enantiomers dissolved in chiral polypeptide liquid crystals. It is shown that an accurate determination of enantiomeric excess is possible within a short experimental time. (C) 2002 Elsevier Science (USA). All rights reserved.