Spin Trapping by Use ofN-Tert-Butylhydroxylamine. Involvement of Fenton Reactions

Spin trapping of short-lived R. radicals is done by use of N-tert-butylhydroxylamine (1) and H2O2. The hydroxylamine is oxidized to the radical t-BuN(O)H (2) which is converted into the spin trap 2-methyl-2-nitrosopropane (3). Simultaneously, hydroxyl radicals .OH are formed from H2O/. The latter radical species abstracts hydrogen atoms from suitable molecules HR to give R. radicals, which are trapped with the formation of aminooxyl radicals, i.e., t-BuN(O)R (4), detectable by EPR spectroscopy. The reaction is enhanced by the presence of iron ions. The cleavage of H2O2 into .OH radicals is considered to involve both a radical-driven (t-BuN(O)H 2) and an iron-driven Fenton reaction.