Novel optically active materials incorporating a 2,4-disubstituted oxazoline ring

Abstract

A series of novel optically active 2,4-disubstituted oxazoline derivatives has been prepared (fig. 1). A systematic study into the effect of the number and position of dipole moments lateral to, and in the aromatic core, on transition temperatures has been undertaken and the results discussed. The alkyl chain (A) at the asymmetric centre has been varied, and the effects of its rigidity and size investigated. The aliphatic chain attached to the aromatic core has also been varied in length.

Significant changes in the physical properties of the materials can be brought about by simple structural modifications. The effect of the addition of these materials into a standard smectic C, A and nematic host mixture has been noted and the observations discussed. An interesting phenomenon was the presence of frustrated phases, such as twist grain boundary and blue phases, when some dopants were added to the host mixture at low concentrations.

Key Words:

• ferroelectric liquid crystal
• asymmetric centre
• optically active dopant
• twist grain boundary phase
• packing arrangements