Synthesis, structural, electrochemical, and spectroscopic studies of some (diimine)ruthenium nitrile complexes

Abstract

The syntheses of cationic ruthenium(II) complexes [Ru(Me₂-bpy)(PPh₃)₂RRʹ][PF₆]x {Me₂-bpy = 4,4ʹ-dimethyl-2,2ʹ-bipyridine, (3) R = Cl, Rʹ = N≡CMe, x = 1, (4) R = Cl, Rʹ = N≡CPh, x = 1, (5) R = Rʹ = N≡CMe, x = 2} and [Ru(Me₂-bpy)(κ²-dppf)RRʹ][PF₆]x {dppf = 1,1ʹ-bis(diphenylphosphino)ferrocene, (6) R = Cl, Rʹ = N≡CMe, x = 1, (7) R = Cl, Rʹ = N≡CPh, x = 1, (8) R = Rʹ = N≡CMe, x = 2} are reported, together with their structural confirmation by NMR (31P, 1H) and IR spectroscopy and elemental analysis, and, in the case of trans-[Ru(Me₂-bpy)(PPh₃)₂(N≡CCH₃)Cl][PF₆] (3), by X-ray crystallography. Electronic absorption and emission spectra of the complexes reveal that all complexes except 4 and 6 are emissive in the range 370–400 nm with 8 exhibiting an emission in the blue. Cyclic voltammetry studies of 3–8 show reversible or quasi-reversible redox processes at ca. 1 V, assigned to the Ru(II/III) couple. Show more