MOLECULAR-DYNAMICS OF A CHIRAL SMECTIC, LIQUID-CRYSTAL AS STUDIED BY C-13 NMR-SPECTROSCOPY

We have investigated the molecular dynamics in the chiral smectic phas es of an antiferroelectric liquid crystal, (S)-4-(1-methylheptyloxy-ca rbonyl)phenyl 4'-octyloxybiphenyl-4-carboxylate ((S)-MHPOBC), by means of the solid-state C-13 NMR spectroscopy The mobility of the spacer c hain is almost constant through the temperature range of the Smectic p hases, while that of the core part decreases with decreasing temperatu re. On the basis of the C-13 NMR spectra, we speculate the model respo nsible for the molecular dynamics. In addition, we have tried to estim ate the correlation time of the motion for the core part.