Laterally aryl-substituted bent-core mesogens

Abstract

Laterally aryl-substituted bent-core mesogens, prepared from 2-methyl-isophthalic acid, were studied. Optical polarising microscopy gave hints for nematic and smectic A phases which were supported by X-ray measurements. Two-dimensional patterns of samples aligned in the magnetic field prove clusters of the smectic C type within the nematic phases. The layer spacings point to intercalated structures because they are significantly shorter than the molecular lengths derived from molecular models. The shape of the molecules seems to be neither rod-like, nor really bent, nor discotic due to the extension of the bending angle caused by the lateral methyl group in a bay position and the different cross-sections of different molecular parts.

Keywords:

• bent-core mesogens
• lateral aryl substituents
• nematic
• smectic A
• smectic C cluster