Inclusions between large flat organic molecules; The induction of columns and mesophases

We describe here an overview on the formation of mesophases by the interaction between large flat aromatic cored molecules and relatively small organic electron accepters which form stacked, sandwich-like columnar pi-pi electron donor-acceptor complexes. The inclusion of suitable donor and acceptor components may be used to induce columnar mesophases in mixtures of compounds which can be either mesomorphic or non-mesomorphic in the pure state. With judicious choice of donor and acceptor partners, induced mesophases of remarkable range and thermal stability can be prepared.