Irradiation of 2-nitrophenyl phenyl sulfoxide (I) gave 2-nitrosophenyl phenyl sulfone (II) as the sole product. The rearrangement was not affected by a quencher, but took a different course in the presence of a sensitizer or a halogen-containing solvent. When I with an electron-donating substituent at a 4′-position or electron-withdrawing one at a 4-position was irradiated, the corresponding II was obtained in a lower yield. 2-Nitrophenyl phenyl ...