COMPARISON WITH SEVERAL OXIDATION-STATES OF RUTHENIUM BINUCLEAR COMPLEXES - RUTHENIUM ANALOG FOR IRON-PROTEIN ACTIVE-SITE MODEL

Alkoxo bridged ruthenium dinuclear complexes as a non-heme diiron prot ein active site model, [Ru(III)(2)(dhpta)(O(2)CR)2](-) =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 coupl ed magnetic behavior (H = -2J . S-1 . S-2, -J=310 similar to 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 th e near-IR region, which the lowest energy one might be intervalence ch arge transfer (IT) band. Hush theory was applied to analyze the IT ban d in the lowest energy, the electronic coupling integral, H-ad was est imated 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 s tate, two absorption bands appeared in the near-IR region, and Had was estimated as 2000 cm(-1).