Reactions of Alkyl and Fluoroalkyl Radicals with Nickel, Iron, and Manganese Prophyrins

Article abstract of DOI:10.1021/j100202a092

The reactions of alkyl (CH3, C2H5, n-C4H9, CH2CO2^-, CH(CO2^-)2, CH2CN) and fluoroalkyl (CF3, CF2Cl) radicals with nickel, iron, and manganese porphyrins (P) have been studied by radiolytic techniques in various solvents.All the radicals (R) react with Fe^IIP to form R-Fe^IIIP with a stable Fe-C bond.These products are oxidized by O2 to Fe^IIIP.Although Ni^IP and Ni^IIP also react rapidly with the radicals to form Ni-C bonds, only the reactions of fluoroalkyl radicals with Ni^IP yield stable products.Reactions of alkyl radicals with Ni^IP result in unstable R-Ni^IIP products (t_1/2 several seconds) that eventually yield Ni^IIP.Reactions of alkyl radicals with Ni^IIP are reversible, and the short-lived R-Ni^IIIP products (t_1/2 ca. milliseconds) disappear through radical reactions, with recovery of Ni^IIP.Alkyl radicals react rapidly with Mn^IIP, probably via addition to the metal, but the adduct gives Mn^IIIP immediately. ^.CF3 radicals also react with Mn^IIIP by addition to C=C bonds.