Preliminary communication Helical superstructures in a novel smectic mesophase formed by achiral banana-shaped molecules

A new smectic type mesophase without in-plane order is presented which is formed by nitro substituted banana-shaped compounds. The structure of this phase is not yet known in detail. The growth of germs and also the textures point to a helicoidal structure. The helical structure is obviously the result of the chirality of the smectic layers which is caused by the tilt of the molecules together with the polar arrangement of the angled molecules.