Ligand-Centered Electron-Transfer Redox Processes for Manganese, Iron, and Cobalt Complexes in Relation to Selected Catalytic Systems
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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The oxidation potentials for a series of Manganese L3, Iron L3 and Cobalt L3 complexes L acetylacetonate, 8-quinolinolate, picolinate, 2,2- bipyridine, and 1,10-phenanthroline have been determined by cyclic voltammetry. The oxidations of these complexes occur at substantially less positive potentials than those for their zinc analogues and care clearly ligand-centered. The removal of an electron from the valence shell of the ligand is facilitated by the formation of a metal d-electron-ligand p-electron covalent bond. Other hydrocarbon substrates are transformed to ketones via the oxygenation of a methylenic carbon. Acetylenes and arylolefins are dioxygenated to alpha- dicarbonyls and aldehydes. A micron-dioxygen binuclear iron picolinate intermediate appears to be the active form of the catalyst. Keywords Oxidation reduction reactions Electrical measurement Measurement.
- Organic Chemistry