Nagao Hirotaka

A dinitrogen-bridged ruthenium dinuclear complex in a mixed-valence state of Ru( ii )–Ru( iii ), [{Ru(κ ² -pydc)(NH ₃ ) ₃ }(μ-N ₂ ){Ru(κ ² -pydc)(NH ₃ ) ₂ (OH)}], has been synthesized by a reaction using dinitrogen or hydrazine as a dinitrogen source.

Ru₂(iv,iv), Ru₂(iii,iv), and Ru₂(iii,iii) complexes with the doubly oxido-/hydroxido-bridged core, {Ru₂(μ-O)₂}, {Ru₂(μ-O)(μ-OH)}, or {Ru₂(μ-OH)₂}, were synthesised with ethylbis(2-pyridylmethyl)amine for all, as structural analogues of sMMO.

In this accounts, syntheses and reactions of ruthenium complexes bearing pyridyl-containing ligands have been described. The properties and reactivity of complexes are related to their geometrical configuration around the metal center, and regulated by the combination of supporting ligands such as bpy, pyca, tpy, and bpya. Ruthenium complexes containing a nitrosyl ligand, which functions as a regulator of reactivity, have been synthesized and their structures and redox properties are investigated. We conclude that the interaction of the nitrosyl ligand through the ruthenium ion strongly depends on an electronic feature of the co-existing ligand in the series of nitrosylruthenium complexes. Conversion reactions of nitrogen-containing compounds such NO₂^- (NO), N₃^-, CH₃CN, and NO₃^- are performed under mild conditions to afford nitrogen-containing ligands. The reactions of N₃^- give two different type of ligands, imine (NH=CHR) and bridging nitrido (-N^3--), depending on supporting ligands. These reactions are important as a synthetic route of nitrogen-containing complexes. A geometrical isomerization and ligand-dissociation reactions are induced by redox of ruthenium comeplxes. The stabilities and reactivities of the ruthenium complexes have been explained by considering the electronic interaction of metal-ligand and ligand-ligand through the ruthenium center.