Controlled photochemical release of nitric oxide from O2-substituted diazeniumdiolates

Diazeniumdiolates are a well-established class of nitric oxide (NO) donors that have been employed in a wide variety of biochemical and pharmacological investigations. To provide a means of targeting NO release, photosensitive precursors to diazeniumdiolates have been developed and are reviewed here. After a brief description of diazeniumdiolate chemistry and the potential uses of photosensitive precursors to NO, three different classes of phototriggered diazeniumdiolates are discussed: 2-nitrobenzyl derivatives, meta-substituted benzyl derivatives, and naphthylmethyl and naphthylallyl derivatives. In addition, the photochemistry of diazeniumdiolate salts themselves is covered.