NEW FLUORINATED NITROXIDES - GENERATION, STRUCTURE, REACTION AND APPLICATION

A large number of fluorinated nitroxides with a wide variety of struct ures have been synthesized by mainly making use of the electron-transf er reactions of fluorinated oxidants, such as (R(f)COO)(2), R(f)I and R(f)SO(2)Br with nitrogen-containing substrates. The nitroxides are sp in-adducts of the radical intermediates and both nitroso traps (R(f)NO or RNO) are formed in these reactions. Such 'in situ spin trapping re actions' have served as a useful technique in the mechanistic studies of these radical reactions of N-substrates. The reaction mixtures - bl ue solutions (called 'magic blue') containing very reactive fluorinate d nitroxides such as R(f)N(O .)R(f) and effective spin traps such as R (f)NO - have been applied successfully to the study of H-abstraction r eactions from very many kinds of substrates and thereby producing a mu ch larger number of fluorinated nitroxides. Much valuable information about the electronegativity of various fluorinated functional groups, substituent effects through spin-delocalization (sigma(.) scale), salv ation, the temperature dependence of a(N) and a(F) values, as well as selective line broadening have been gained from EPR studies of these n ew fluorinated nitroxides.