PHOTOTRANSFORMATION OF 2-PHENYLPHENOL INDUCED IN AQUEOUS-SOLUTION BY EXCITATION OF NITRATE IONS

The formation of several photoproducts was observed in the phototransf ormation of 2-phenylphenol (II) induced by excitation of nitrate ions: 2-hydroxy-3-nitrobiphenyl (IV), 2-hydroxy-5-nitrobiphenyl (VI), pheny lhydroquinone (VII), phenylbenzoquinone (VIII) and 2-hydroxydibenzofur an (M). The photolysis of nitrate ions leads to the formation of hydro xyl radicals and nitrogen dioxide. W results from the oxidation of II by hydroxyl radicals. VII is oxidized into WI which is photocyclised i nto IX. The formations of IV and Vl are enhanced in acidic solution. T hey are attributed to a reaction of a nitrogen oxide, NO2 or N2O4. Thi s reaction competes with the disproportionation into nitrite and nitra te ions. The accelerated formation of IV and VI can be attributed to t he excitation of nitrite ions.