Measurement and Analysis of the Molecular Ordering Tensors of Two Enantiomers Oriented in a Polypeptide Liquid Crystalline System

Philippe Lesot (1) , Yves Gounelle (1) , Denis Merlet (1) , Aharon Loewenstein (1) , Jacques Courtieu (1)

1 ICMMO - Institut de Chimie Moléculaire et des Matériaux d'Orsay

High-resolution proton and natural abundance carbon-13 NMR spectra of a rigid chiral molecule, (+/-)-p- (trichloromethyl)-beta-propiolactone, dissolved in the liquid-crystalline phase of poly(gamma-benzyl-L-glutamate) (PBLG), in methylene chloride, were analyzed. From the NMR data and the X-ray structure, the full order matrix was determined and analyzed in detail for each optical isomer of the molecule. It is shown that the spectral discrimination of the enantiomers in this lyotropic medium arises mainly from the difference in their average molecular orientation and the principal axis systems of orientation are compared.

Mots clés: Order parameter; Chiral liquid crystal; PBLG; NMR; Carbon-13; Saupe matrix

Domaines: Chimie analytique

Philippe Lesot, Yves Gounelle, Denis Merlet, Aharon Loewenstein, Jacques Courtieu. Measurement and Analysis of the Molecular Ordering Tensors of Two Enantiomers Oriented in a Polypeptide Liquid Crystalline System. The Journal of physical chemistry, 1995, 99 (40), pp.14871-14875. ⟨10.1021/j100040a042⟩. ⟨hal-02309083⟩