Laser flash photolysis study of photoionization in fluoroquinolones

Abstract

A laser flash photolysis investigation was carried out on the mechanism of electron photoejection in fluoroquinolone derivatives, bearing either electron donating or electron accepting substituents in position 8, laser excited at λ_exc = 355 nm in neutral aqueous solutions. The dependence of the hydrated electron absorption at 720 nm on the laser intensity and on the presence of N₂O as electron scavenger evidenced that in enoxacin, norfloxacin, and lomefloxacin the photoionization is predominantly two-photon. With rufloxacin, besides the two-photon process, a one photon contribution with a quantum yield of 0.034 was measured.