Macroscopic evidence of molecular chirality in columnar mesophases

Besides the classical liquid crystals observed with rod-like molecules (nematic and smectic mesophases) and plastic crystals obtained in the case of globular compounds, two new classes of thermotropic mesophases consisting of two-dimensional aromatic flat molecules have been investigated 1–3 : D columnar mesophases (columns of disk-like molecules in regular two-dimensional periodic array) and N D nematic mesophase (disk-like molecules parallel to an average plane). We report here two examples of molecular chirality directly observable in D mesophases of a resolved disk-like compound.