Host-guest chemistry aids and abets a stereospecific photodimerization in the solid state

Abstract

A bis(dialkylammonium ion)-substituted stilbene derivative cocrystallizes with bisparaphenylene[34]crown-10 to form, in the solid state, a 2:2 host-guest complex wherein the stilbene double bonds are aligned with a relative geometry suitable for a stereospecific photochemical [2+2] cycloaddition. When irradiated with white light, this crystalline complex forms a single diastereoisomer of the corresponding cyclobutane derivative (see schematic presentation), the stereo-chemistry of which has been determined unambiguously in the solid state by X-ray crystallography to be syn-anti-syn.