Synthesize of banana-shaped liquid crystals with a seven-membered ring as a central core (2)

Abstract

The synthesis and characterization of achiral banana-shaped compounds with a seven-membered ring as a central core are reported. One of the advantages to use a seven-membered ring is to make the bend angle shaper. Further, the seven-membered ring has an electro-withdrawing carbonyl group at the central position, which could play a role to induce a B7 phase. In fact, 1,3-bis[4-(4-alkyloxyphenyliminomethyl)-benzoyloxy]tropones show banana phases. From the observation of the optical texture, the phase at higher temperature is assigned to be B7 phase and the phase at lower temperature SmCsP phase.