DISCRIMINATION AND ANALYSIS OF THE NMR-SPECTRA OF ENANTIOMERS DISSOLVED IN CHIRAL LIQUID-CRYSTAL SOLVENTS THROUGH 2D CORRELATION EXPERIMENTS

The discrimination and analysis of the NMR spectra of optically active molecules dissolved in chiral liquid crystal solvents through 2D corr elation experiments is studied. The technique allows the identificatio n of the line positions of each enantiomer, thus providing a notable s implification of the spectral analysis. The 2D HOHAHA and multiple-qua ntum experiments are investigated and discussed. The potential of the method is illustrated using a sample of (+/-) 3,3,3-trichloroepoxyprop ane dissolved in a thermotropic cholesteric solvent. The case of chira l molecules bearing a fluorine or deuterium nucleus has also been stud ied. In addition, it is shown that 2D heteronuclear correlation experi ments are powerful methods for correlating carbon and proton spectral data of two enantiomers. A specific example is given through (+/-) 2-b romopropanoic acid dissolved in a lyotropic polypeptide liquid crystal . Spectral parameters of each enantiomer are calculated for the differ ent examples.