Syntheses and characterization of η5-cyclopentadienyl and η5-indenyl ruthenium(II) complexes of arylazoimidazoles: The molecular structure of the complex [(η5-C5H5)Ru(PPh3)(C6H5–NN–C3H3N2)]+

The complex [(η5-C5H5)Ru(PPh3)2Cl] (1) reacts with several arylazoimidazole (RaaiR′) ligands, viz., 2-(phenylazo)imidazole (Phai-H), 1-methyl-2-(phenylazo)imidazole (Phai-Me), 1-ethyl-2-(phenylazo)imidazole (Phai-Et), 2-(tolylazo)imidazole (Tai-H), 1-methyl-2-(tolylazo)imidazole (Tai-Me) and 1-ethyl-2-(tolylazo)imidazole (Tai-Et), gave complexes of the type [(η5-C5H5)Ru(PPh3)(RaaiR′)]+ {where R, R′ = H (2), R = H, R′ = CH3 (3), R = H, R′ = C2H5 (4), R = CH3, R′ = H (5), R, R′ = CH3 (6), R = CH3, R′ = C2H5 (7)}. The complex [(η5-C9H7)Ru(PPh3)2(CH3CN)]+ (8) undergoes reactions with a series of N,N-donor azo ligands in methanol yielding complexes of the type [(η5-C9H7) Ru(PPh3)(RaaiR′)]+ {where R, R′ = H (9), R = H, R′ = CH3 (10), R = CH3, R′ = H (11), R = CH3, R′ = C2H5 (12)}, respectively. These complexes were characterized by FT IR and FT NMR spectroscopy as well as by analytical data. The molecular structure of the complex [(η5-C5H5)Ru(PPh3)(C6H5–NN–C3H3N2)]+ (2) was established by single crystal X-ray diffraction study.

The reaction of [Cp′Ru(PPh3)2Cl] (Cp′ = C5H5, C9H7) with arylazoimidazole (RaaiR′) ligands in the presence of ammonium hexafluorophosphate generates greenish-brown and brown colored mononuclear cationic complexes [Cp′Ru(PPh3)(RaaiR′)]+. The representative complex 2 has been established by X-ray diffraction study.Figure optionsDownload as PowerPoint slide