We designed and synthesized a photocontrollable peroxynitrite (ONOO–) generator, P-NAP, which has N-methyl-N-nitrosoaminophenol structure with four methyl groups introduced onto the benzene ring to block reaction of the photodecomposition product with ONOO–and to lower the semiquinoneimine's redox potential. The semiquinoneimine intermediate generated by photoinduced release of nitric oxide (NO) reduces dissolved molecular ...