The solid state photoreactions of mixed crystals of acetylcoumarins and indole were investigated, and the mixed crystals were characterized by solid UV spectra, solid FL spectra and X-ray powder diffraction analysis. The photoreactions of 3- acetylcoumarin and its 7-acetyloxy, 7-benzoyloxy, 6-bromo and 5,6-benzo derivatives with indole in the solid state afforded condensation products 1～5, respectively, while 3-acetyl-6- nitrocoummarin with indole gave ring cleavage decarbonyl addition product 6. The products were identified by IR, ^1H NMR, MS and elemental analyses.

Key words: INDOLE, STRUCTURE CHARACTERISTICS, ACETYL GROUP, X-RAY DIFFRACTION ANALYSIS, MIXED CRYSTALS, SOLID PHASE REACTION, SPECTROGRAPHIC ANALYSIS, COUMARIN P, PHOTOCHEMICAL REACTION