Pyridazine N -Oxides as Photoactivatable Surrogates for Reactive Oxygen Species.

A method for the photoinduced evolution of atomic oxygen from pyridazine N -oxides was developed. This underexplored oxygen allotrope mediates arene C-H oxidation within complex, polyfunctional molecules. A water-soluble pyridazine N -oxide was also developed and shown to promote photoinduced DNA cleavage in aqueous solution. Taken together, these studies highlight the utility of pyridazine N -oxides as photoactivatable O( 3 P) precursors for applications in organic synthesis and chemical biology.