Solvent-induced crystalline-state emission and multichromism of a bent π-surface system composed of dibenzocyclooctatetraene units.

All bent out of shape: The solvent of crystallization effectively enhances the emission of flexible, bent, π-conjugated molecules in the crystalline state owing to control of the packing of the molecules in the structure. Multichromism such as thermochromism and vapochromism also arises from the solvent-controlled packing. This crystalline-state emission is attributable to the flexibility of cyclooctatetraene units of the bent π-conjugated molecules in the solid state (see figure).