13C NMR Observation of Molecular Motions at the Smectic-A-Smectic-C (Smectic-C*) Transition in a Recemic (Chiral) Smectic Liquid Crystal

Abstract
We have studied molecular motions and the microscopic environment at the SmA-SmC (SmC*) transition in a racemic (chiral) smectic liquid crystal by means of 13C NMR with CP/MAS and without sample spinning. Fast overall fluctuation caused by the existence of the molecular chirality has been observed in the SmA phase by T 1 measurements. Static NMR spectra indicate that the conformation of the enantiomer in the SmC* phase is different from that of the corresponding racemic compound in the SmC phase.