6533b861fe1ef96bd12c5778

RESEARCH PRODUCT

Kinetic and Thermodynamic Studies of Iron(III) and Iron(IV) σ-Bonded Porphyrins. Formation and Reactivity of [(OEP)Fe(R)]n+, Where OEP Is the Dianion of Octaethylporphyrin (n = 0, 1, 2, 3) and R = C6H5, 3,4,5-C6F3H2, 2,4,6-C6F3H2, C6F4H, or C6F5

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description

A series of high- and low-spin iron(III) phenyl and fluorophenyl octaethylporphyrin complexes are characterized by their electrochemical and spectroscopic properties in nonaqueous media. The investigated compounds are represented as (OEP)Fe(R), where R = C6H5, 3,4,5-C6F3H2, 2,4,6-C6F3H2, C6F4H, or C6F5 and OEP is the dianion of 2,3,7,8,12,13,17,18-octaethylporphyrin. The two C6F3H2 complexes are of special interest in that these isomers differ in the spin state of the iron(III). Electrochemical studies indicate that three one-electron oxidations are seen for all of the (OEP)Fe(R) derivatives which were investigated both at room and low temperature under conditions where migration of the σ-bonded ligand does not occur on the time scale of the experiment. The first one-electron oxidation of each compound leads to an Fe(IV) porphyrin, and this is followed by a migration of the axial group from the iron center to one of the four nitrogen atoms independent of the nature of the axial group or the iron(III) spin...