Comparison with Several Oxidation States of Ruthenium Binuclear Complexes; Ruthenium Analogue for Iron- Protein Active Site Model

Abstract

Abstract Alkoxo bridged ruthenium dinuclear complexes as a non-heme diiron protein active site model, [Ru(III)2(dhpta)(O2CR)2]− (H5dhpta=1, 3-diamino-2- hydroxypropane-N,N,N′,N′-tetraacetic acid, R=CH3(1), C6H5(2), C6H4-p-OH(3), C6H4-p-NH2(4)) exhibited the strongly antiferromagnetically coupled magnetic behavior (H = −2J*S 1*S2, -J=310∼470 cm−1). The magnetic interaction between Ru(III) ions varies depending on the bridged carboxylato ligand. The one- electron reduced Ru(II)Ru(III) mixed-valence states by electrolysis shows two absorption bands in the near-IR region, which the lowest energy one might be intervalence charge transfer (IT) band. Hush theory was applied to analyze the IT band in the lowest energy, the electronic coupling integral, Had was estimated to be 670–870 cm−1. The interaction between the Ru(II)Ru(III) mixed valence state is weaker than that of the Ru(III)Ru(III) states. With one-electron oxidized complex (2), Ru(III)Ru(IV) mixed-valence state, two absorption bands appeared in the nea...