Dinuclear Fe(II) macrocyclic complexes as catalysts for the oxidation of hydrocarbons by molecular oxygen

Two dinucleating macrocyclic ligands [24]RBPyBC and [30]RBBPyBC, containing phenolate pyridine, bipyridine, and amino groups form dinuclear Fe(II) and Fe(III) complexes in which the Fe(II) and Fe(III) centers are coordinated and bridged by the phenolate groups. The dinuclear iron(II) complexes of these ligands react with molecular oxygen and catalyze its insertion into cyclohexane and adamantane in the presence of a two-electron reductant, such as H2S. The hydrocarbons are mainly hydroxylated but some ketonization product is also formed. The reaction rates and yields compare favorably with other catalytic systems. A possible mechanism is suggested for the hydroxylation reaction.