Hydroperoxyl Radicals (HOO center dot): VitaminE Regeneration and H-Bond Effects on the Hydrogen Atom Transfer

Hydroperoxyl (HOO.) and alkylperoxyl (ROO.) radicals show a different behavior in H-atom-transfer processes. Both radicals react with an analogue of -tocopherol (TOH), but HOO., unlike ROO., is able to regenerate TOH by a fast H-atom transfer: TO.+(HOOTOH)-T-.+O-2. The kinetic solvent effect on the H-atom transfer from TOH to HOO. is much stronger than that observed for ROO. because noncovalent interactions with polar solvents (SolvHOO(.)) destabilize the transition state.