Light-driven phase transition in a cubic-phase-forming binary system composed of 4'-n-docosyloxy-3'-nitrobiphenyl-4-carboxylic acid and an azobenzene derivative.

Binary mixtures were prepared from an azobenzene derivative and a liquid-crystal (LC) compound that exhibits smectic C (SmC) and bicontinuous cubic (Cub(bi)) LC phases. Reversible switching between the two phases in response to UV-light irradiation was observed. This light-driven SmC-to-Cub(bi) transition is the first example showing the increased dimensionality of molecular ordering with isomerization of azobenzenes (see figure).