title: Photolysis of nitrosamines and nitrosamides at neutral pH: a spin-trap study.
abstract: A model system has been used to study the types of radicals formed on denitrosation of N-nitroso compounds. Free radicals were formed at room temperature (22 degrees-23 degrees C) and neutral pH by photolytic cleavage of N-nitroso bonds and were partially characterized following their addition to the spin traps 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) and N-tert-butyl-alpha-phenyl-nitrone (PBN). Carbon-centered radical adducts were obtained during nitrosamine photolysis and nitrogen-centered radical adducts during nitrosamide photolysis. Since both the nitrosamines and nitrosamides initially form nitrogen-centered radicals on photolysis, a secondary reaction or rearrangement must occur after initial N-nitroso bond cleavage in the nitrosamines. Mechanisms are proposed to account for these results.
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D006863:Hydrogen-Ion Concentration; D009602:Nitrosamines / Q000528:radiation effects*; D009603:Nitroso Compounds / Q000528:radiation effects*; D010782:Photolysis; D013113:Spin Labels
chemical_list: D005609:Free Radicals; D009602:Nitrosamines; D009603:Nitroso Compounds; D013113:Spin Labels; C013621:nitrosamides