Mesogenic β-diketones and metallonematogens

Abstract

Several new liquid-crystalline materials have been synthesized and their properties investigated. These belong to a series β-diketones containing different terminal substituents Mesophases of the smectic C, smectic A and nematic types have been observed in these β-diketones. Using these ligands many copper(I1) and palladium(I1) complexes have also been synthesized and their mesogenic behaviour characterized. Microscopic observations and diNeerentia1 scanning calorimetric measurements show that these chelates exhibit the nematic phase. The DSC data also indicate that the nematic phase of the ligands and complexes is associated with very low clearing transition enthalpies. All the metallonematogens reported are enantiotropic in nature.