Abstract
A series of liquid crystalline cyclic siloxane tetramers was prepared to investigate, in a systematic manner, the role of molecular structure of (a) the spacer group, (b) the mesogenic side group and (c) the chiral end group, on the liquid crystalline behaviour of these novel tetramers. The results from this systematic structure/property correlation study clearly showed the effects of the structure of the chiral end group and the mesogenic side group on the thermal stability and temperature range of the SmC* phase (ferroelectric) exhibited by these materials. For a given chiral end group, the effect of the length of the spacer group on the thermal stability and temperature range of the SmC* phases depended greatly on the structure of the mesogenic side group. By appropriate choice of spacer group, mesogenic side group and chiral end group, a number of tetramers exhibiting wide SmC* ranges (ferroelectricity) from below room temperature were synthesized.