Molecular dynamics of a chiral smectic liquid crystal as studied BY¹³C NMR spectroscopy

Abstract

We have investigated the molecular dynamics in the chiral smectic phases of an antiferroelectric liquid crystal, (S)-4-(1-methylheptyloxy-carbonyl)phenyl 4′-octyloxybiphenyl-4-carboxylate ((S-MHPOBC), by means of the solid state ¹³C NMR spectroscopy. The mobility of the spacer chain is almost constant through the temperature range of the Smectic phases, while that of the core part decreases with decreasing temperature. On the basis of the ¹³C NMR spectra, we speculate the model responsible for the molecular dynamics. In addition, we have tried to estimate the correlation time of the motion for the core part.

Key Words:

• ferroelectric liquid crystal
• phase transition
• NMR
• molecular dynamics
• antiferroelectricity