ENANTIOMERIC ANALYSIS OF HOMOLOGOUS SERIES OF SECONDARY ALCOHOLS BY DEUTERIUM NMR-SPECTROSCOPY IN A CHIRAL NEMATIC LIQUID-CRYSTAL - INFLUENCE OF MOLECULAR-GEOMETRY ON CHIRAL DISCRIMINATION

NMR measurements of the differential ordering effect (DOE) are present ed for homologous series of 22 chiral secondary aliphatic alcohols dis solved in a poly-(gamma-benzyl-L-glutamate) (PBLG)/dichloromethane liq uid-crystalline solvent. The quadrupolar splittings of the solutes, wh ich were deuterated at their chiral centres, were measured as a functi on of the PBLG concentration and temperature. The proton dipolar split tings of the dichloromethane in each sample were also measured and use d as a reference. The results are analysed qualitatively in terms of t he structures of the molecules and their asymmetric (or chiral) charac teristics. Emphasis is put on comparative analysis of the chiral discr imination in members of each particular homologous series and on evalu ating the Limits of the technique for molecules that have two very sim ilar groups attached to their stereogenic centres.