SYNTHESIS AND PHASE-BEHAVIOR OF CHIRAL LIQUID-CRYSTALLINE COMPOUNDS WITH THE STRUCTURE OF L-AMINO-ACID DERIVATIVE

Nine mesogenic compounds (I - III, IVa, b, V-a,V- b, VIa, b) with the structure of L-amino acid derivative, four L-amino derivatives (A(1-4)) and six mesogenic compounds (M(1-6)) were synthesized. The chemical structure of new compounds (I - III, IVa, b, V-a,V- b, VIa, b, A(4) and M(3-6)) were confirmed by IR, H-1 NMR and elemental analysis. Their phase behavior was also investigated by using differential scanning calorimetry (DSC) and polarizing microscopy, The resultis show that eight compounds (M(3-6), IVa, b, V-b and VIb) exhibit the liquid crystalline plase transtion temperatures, The specific rotation of the compounds was also determined, X-Ray diffraction had been used to investigate smectic structure of two compounds, the results show that compounds (IVb, VIb) exhibit S-c* and S-E* respectively. The hysteresis loop of IVb were determined, it is proved that VIb do have ferroelectricity.