Mesophases Induced by Molecular Complexing

By mixing of potentially-mesomorphic electron donors and acceptors of the type N-(p-X-benzylidene)-p-Y-aniline, nematic and smectic liquid crystals could be induced. In the present work, the donor molecules with a dimethylamino group as X or Y and the acceptor molecule with a nitro group as X or Y were employed. The remaining terminal substituents were selected from short alkoxyl groups; namely, methoxyl, ethoxyl, and propoxyl groups. The effect of the replacement of ethoxyl group by propyl group was also studied. The induced mesophases are more deeply colored than the component compounds owing to the appearance of intermolecular charge-transfer absorption near 500 nm.