Oxazoline derivatives exhibiting chiral liquid crystalline mesophases

We have designed new chiral mesogens, OXm/n, containing an oxazoline chiral motif derived from natural L-serine amino acid. Our effort was concentrated on the evaluation of the synthetic accessibility of these new compounds and preserving their optical purity, which was determined using chiral high-performance liquid chromatography. We established materials mesomorphic properties and confirmed the phase identification by X-ray scattering studies. Depending on the ratio between the terminal alkyl chain lengths, the studied materials exhibited various smectic mesophases. The derivatives OXm/n with conformationally rigid oxazoline chiral moiety were compared with the structurally similar smectogens, ZLm/n, having a flexible (S)-lactate chiral unit, in order to investigate the effect of rigidisation of the chiral unit on the mesomorphic properties.