Formation of Doubly Nitrosyl-Bridged Diruthenium Complex Bearing Tridentate Ethylbis(2-pyridylethyl)amine via Conversion of Nitrate

A doubly nitrosyl-bridged dinuclear ruthenium complex, {Ru2(µ-NO)2}, bearing tridentate ethylbis(2-pyridylethyl)amine (ebpea) and acetonitrile as supporting and co-existing ligands, respectively, [{Ru(µ-NO)(ebpea)(NCMe)}2]2+ ([1]2+) has been synthesized by a reaction of tris(acetonitrile)ruthenium(II) complex with sodium nitrate in ethanol. The ebpea ligand coordinated with two pyridyl- and one amine-nitrogen atoms in a meridional mode. The dinuclear ruthenium complex containing two nitrosyl ligands bridging between two ruthenium centers as a bending mode, showed two stepwise one-electron oxidation waves at 0.03 and 0.57 V vs. Ag|0.01 M AgNO3 in MeCN and a strong characteristic NO stretching vibrational mode ν(NO) at 1336 cm−1, indicating the electronic structure of the {RuNO}-moieties was an octahedral {RuNO}8-type. The dinuclear ruthenium complex reacted with acid to give mononuclear ruthenium complexes with evolution of dinitrogen oxide.