DERIVATIVES OF DIHYDROPYRAZINE-1,4-DIOXIDE, 3-IMIDAZOLINE 3-OXIDE, AND ALPHA-PHENYL NITRONES WITH FUNCTIONAL-GROUPS AS NEW SPIN TRAPS IN SOLUTION AND IN THE GAS-PHASE

The title compounds, acyclic phenyl nitrones with functional groups, c yclic dinitrones with conjugated or isolated double bonds, and imidazo line nitrones are studied as spin traps (ST) for short-lived free radi cals (R) generated photochemically in solution and in the gas phase. N ew STs are efficient in trapping OH, hydroxyalkyl, or HO2 radicals. EP R spectra of the spin adducts (SA) of studied dinitrones are triplets of doublets characteristic of the nitroxides with one radical center. Imidazoline ST with amino nitrogen exhibits pH-dependent hyperfine spl ittings of its SAs. Some spin traps were shown to be efficient in dete cting R in the atmospheric experiments.