Photolysis of the Phenoxy Radical in a Nitrogen Matrix

The photolysis of the phenoxy radical trapped in solid nitrogen at 4.2°K is studied by use of infrared and visible-ultraviolet absorption spectroscopy. The trapped phenoxy radicals are produced by the photolysis of a parent compound (phenol, anisole, or phenetole) suspended in the solid nitrogen. When light not absorbed by the parent compound is used to decompose the trapped phenoxy radical, product bands grow at 4.68 μ, 4.72 μ, and 2600 Å. The 4.68-μ band has been assigned to carbon monoxide. The 4.72-μ and 2600-Å bands are probably due to trapped 6-oxo-1,3,5-hexatrienyl-1 radicals. The mechanism proposed to account for these products is that absorption of a light quantum by a phenoxy radical breaks the bond between the 1 and 2 ring carbon atoms to produce an excited 6-oxo-1,3,5-hexatrienyl-1 radical. This excited radical may either decompose to yield carbon monoxide or be deactivated and trapped.