Solid‐State Photodimerization of Azaanthracene Derivative Based on a [4+4] Cycloaddition

Abstract A water‐soluble photoactive azaanthracene derivative was synthesized. Its structure was determined by single‐crystal XRD analysis. Then, [4+4] photodimerizations were studied both in solution and in the solid state. Owing to the suitable preorganization of the monomers, solid‐state photodimerization was realized in quantitative yield with high selectivity.