THE NOVEL PHOTOCHEMICAL BEHAVIOR OF TRIPTYCENE-1,4-QUINONE

Triptycene-1,4-quinone (1) reacts photochemically in solution to give different products depending on the solvent employed and on the presen ce or absence of oxygen. The structures of the photoproducts have been elucidated by spectroscopic methods, independent synthesis and single crystal X-ray diffractometry, and possible mechanistic pathways leadi ng to their formation are presented and discussed. Unexpectedly, quino ne 1 was found to be photochemically inert in the crystalline state. T he X-ray crystal structure of 1 reveals the probable reason for this b ehavior.