Photogeneration of hydrated electrons, nitrogen-centered radicals and singlet oxygen from naphazoline: A laser flash photolysis study

The transient intermediates involved in the photochemistry of naphazoline ( NP, 2-[1-naphthylmethyl]imidazoline) have been examined using laser hash ph otolysis techniques. The photoreactivity of the drug is characterized by a photoionization process occurring through a mixture of mono- and biphotonic pathways. An intramolecular electron transfer involving both the imidazoli ne and the naphthalene moieties leads to the formation of nitrogen-centered radicals. The generation of singlet oxygen from the lowest excited triplet state of NP is also observed. The results obtained demonstrate the potenti al for NP to act as a both a type I and type II photosensitizer.