Abstract
Synthetic model complexes, (Et4N)[Fe(S-p-C6H4X)4], for the oxidized form of rubredoxin (Rd) were prepared in CH3CN solution by the ligand-substitution of (Et4N)[Fe(S2-o-xyl)2] with diaryl disulfides in The presence of o-xylene-α, α'-dithiol. The complex (X=H) exhibited an intense electron spin resonance (ESR) signal at g=4.3, due to the Fe(III) metal with the highly symmetrical ligand. The complex in the reduced state, [Fe(S-p-tol)4]2-, was found to reduce tert-butyl hydroperoxide to tert-butyl alcohol stoichiometrically. Rubredoxin is believed to act as an electron carrier in the reduction of alkyl hydroperoxides to the corresponding alcohols in the ω-hydroxylation of alkanes in Pseudomonas olevorans. Thus, the reaction could be considered as biomimetic reduction by a rubredoxin model complex. The reaction mechanisms are discussed in connection with the characterization of the novel complexes.
