Liquid crystalline analogues of curcumin

Abstract

Compounds that are modifications of curcumin were synthesised and their mesogenic properties were studied. The central keto-enolic ring in curcumin was replaced by either a pyrazole or an isoxazole ring. This gives compounds that can form liquid crystalline phases. When two alkoxy chains are attached to the molecule, nematic and lamellar phases appear; in the case of six alkoxy chains, a hexagonal columnar phase is created. The columnar phase is constructed from columns that in the cross-section have two molecules. The pyrazole derivatives in the columnar phase preserve N–H–N hydrogen bonding.

Keywords:

• curcumin
• pyrazole and isoxazole derivatives
• liquid crystals

Funding

This work was supported by UMO-2012/07/B/ST5/02448 grant.