H-shaped liquid crystalline dimers

Abstract

New series of dimers built of two mesogenic units with different end groups linked laterally (H-shaped) by an n-alkyl spacer were synthesised. The liquid crystalline properties of dimers were compared to those of related monomers. The clearing temperatures of H-shaped molecules show only weak dependence on the spacer length and parity, which suggests a folded rather than an all-trans conformation of the spacer. For chiral compounds, the electric polarisation was found to be much lower for dimers than for related monomers, which was explained by partial compensation of intramolecular dipole moments.

Keywords:

• dimers
• liquid crystals
• H-shaped molecules
• chiral compounds