The species responsible for hydrocarbon activation and formation of al
kyl chlorides in the Fen and Fe-III-H2O2 and tert-butyl hydroperoxide
systems are identified. The importance of the Fe-II-Fe-IV manifold in
providing a mechanism which permits the selective functionalization of
saturated hydrocarbons by; ionic trapping with chloride, azide, and o
ther anions is made manifest. Comparison is made with the Fe-III-Fe-V
manifold where ionic trapping is never seen.