SOLID-STATE PHOTOADDITION REACTIONS IN POLYCRYSTALLINE MIXTURES OF NH HETEROAROMATIC-COMPOUNDS AND TRANS-STILBENE

Photoaddition reactions of indole (la), carbazole (Ib) and phenothiazine (Ic) to trans-stilbene (2) occurred in the mixed crystal state to give the corresponding adducts 3a, 3b and 3C with an N-C bond. Photoadduct 4a with a C-C bond was also obtained by the solid state photoreaction of la with 2. The mixed crystals prepared by the melting and resolidifying method were simple polycrystalline mixtures of the two components, and the photoreactions proceeded at the interface of the two crystallites. The selectivity of the photoaddition reaction was higher in the solid state than in solution.