Abstract
The homologous series of three ring chiral esters with terminal chains, one 1-methylheptyl group and, one alkanoyloxyhexyloxy group, were studied. Compounds of these series are liquid crystals with smectic phases, that is, SmA, SmC* (ferroelectric phase) and SmC*A (antiferroelectric phase). The helical pitch was measured by a spectrophotometric method of selectively reflected light. It was found that the helical pitch increases and then decreases with temperature in the SmC*A phase for most homologues and in the SmC* phase for one homologue. The temperature characteristics of the helical pitch are related to the change in handedness of the helix.
Acknowledgement
This work has been carried out under grant PBW-514.