Synthesis, Characterization, and Dioxygen Reactivity of Tetracarboxylate-Bridged Diiron(II) Complexes with Coordinated Substrates

The synthesis and characterization of [Fe2((mu)-O2CArTol)4L2] complexes, where L is benzylamine or 4-methoxybenzylamine (BApOMe), are described. The reaction of the latter diiron(II) complex with dioxygen at -78 °C affords a metastable mixed-valent Fe(II)Fe(III) green intermediate. When O2 is introduced at ambient temperature, N-dealkyation occurs to yield anisaldehyde, eliminating N-oxidation as a viable pathway for the reaction. Use of [Fe2((mu)-O2CArT l)4((alpha)-d1-BAp-OMe)2] allowed a deuterium kinetic isotope of ~3 to be determined.