REDOX KINETICS OF METAL-COMPLEXES IN NON-AQUEOUS SOLUTIONS .5. KINETICS AND MECHANISM OF THE IRON(II) REDUCTION OF THE ACETYLACETONATES OF MANGANESE(III) AND COBALT(III) IN ACETONITRILE

The electron transfer step of the reduction of Mn(acac)3 and Co(acac)3 by Fe(II) in acetonitrile is preceded by the one‐ended dissociation of an acac ligand and the formation of a binuclear bridged complex. After the electron transfer has taken place through the bridging ligand, the complex dissociates into the products M(acac)2 (M = Mn, Co) and Fe(acac)2+. These primary reaction products could not be identified, since the transfer of acac from M(acac)2 to Fe(acac)2+ is too rapid, producing ultimately Fe(acac)3 and M2+. The M(III)‐oxygen cleavage is accelerated by M(acac)2. Furthermore, the dissociation of the binuclear intermediate is catalyzed by the M(acac)3 reactant. Mn(acac)3 is reduced more than a thousand times faster than Co(acac)3. Copyright © 1979 John Wiley & Sons, Inc.