A series of fluorinated liquid crystals with an alanine residue

A series of fluorinated compounds with an L-alanine residue are synthesised. Both enantiotropic SmA and SmC* phases were identified. The clearing points decreased with increasing the alkoxy chain length. The intramolecular hydrogen bond was proposed to decrease the melting points of them and broaden the temperature ranges of the mesophases. The optical purity also played an important role in the thermostability of the mesophases. The compounds derived from L-butyrine and L-norvaline also show SmA and SmC* phases. The clearing point decreases with increasing the alkyl chain length of the amino acid residue.