Á. Costela, J. Dabrio, J. Figuera
Dec 27, 1995
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Influential Citations
11
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Journal
Journal of Photochemistry and Photobiology A-chemistry
Abstract
Abstract The photochemistry at 308 nm of the photoinitiator 4-[2′- N - N -(diethylamino)ethoxy]-benzophenone was studied. The phosphorescence emission and lifetime of the lowest triplet state were characterized. The 4-alkymiminoketyl radical was generated in the ground state through hydrogen atom abstraction by the lowest triplet state of the initiator. The intermolecular vs. intramolecular character of this process was analysed. The radical was excited to the first doublet excited state using 340 nm pulses from a dye laser. The temporal evolution of the radical concentration in the ground and excited states ws followed by laser-induced fluorescence (LIF) and fluorescence intensity measurements respectively. The quenching of the ketyl radical in the ground and excited states by its precursor, O 2 methyl methacrylate and styrene was determined. The effect of the solvent on the quenching of the ketyl radical was studied. Detailed studies on the radical fluorescence were also performed.