Absolute asymmetric photocyclization in chiral diarylethene co-crystals with octafluoronaphthalene.

A photochromic diarylethene containing naphthyl groups formed a chiral crystal when co-crystallized with octafluoronaphthalene, although both molecules are achiral, and underwent highly enantioselective photocyclization owing to the conformational confinement in the crystal.