Enantiomeric excess dependence of the phase diagram of antiferroelectric liquid crystals.
The phase diagram of the prototype antiferroelectric liquid crystal 4-(1-methylheptyloxycarbonyl)phenyl-4'-octyloxybiphengl-4-carboxylate (MHPOBC) in dependence of enantiomeric excess was measured. It was shown that the Sm-C*beta phase in very pure samples is the Sm-C*(FI2) phase with a four-layer structure, and only after small racemization it transforms into the ferroelectric Sm-C* phase. The phase diagram was theoretically explained by taking into account longer range bilinear and short range biquadratic interlayer interactions, that lead to the distorted clock structures and first-order transitions between them.
Chemistry Department, Warsaw University, Al. Zwirki i Wigury 101, 02-089 Warsaw, Poland.
E
E
Gorecka
D
D
Pociecha
M
M
Cepic
B
B
Zeks
R
R
Dabrowski