Heteroleptic ruthenium(II)/(III) 2,2′-bipyridine/1,10-phenanthroline complexes incorporating bidentate Schiff base N,O-ligands

Abstract

Eight substituted bidentate Schiff base ligands HOC6H4CH=N-R (HL) (HL1: R = 4-ClC6H4, HL2: R = 2-ClC6H4, HL3: R = 4-NO2C6H4, HL4: R = 4-MeC6H4, HL5: R = 2,6-Me2C6H3, HL6: R = 2,46-Me3C6H2, HL7: R = CH2C6H5, and HL8: R = n-Pr) were synthesized by the typical condensation reaction. Interaction of cis-[Ru(bpy)2Cl2]⋅2H2O (bpy = 2,2′-bipyridine) with one equivalent of HL ligand in the presence of KPF6 afforded the cationic ruthenium(II) complexes of the type [Ru(bpy)2(L)](PF6) (1–8). The reaction of cis-[Ru(phen)2Cl2]⋅2H2O (phen = 1,10-phenanthroline) and HL1 under similar condition gave complex [(phen)2Ru(L)](PF6) (1a). Treatment of cis-[Ru(phen)2Cl2]⋅2H2O with two equivalents of HL in the presence of KPF6 resulted in isolation of the cationic ruthenium(III) complexes of the type [Ru(phen)(L)2](PF6) (9-16). All complexes have been spectroscopically characterized. The structures of 1a⋅CH2Cl2, 2⋅½CH2Cl2, 3⋅CH3CN, 5⋅½H2O, 6, 12⋅½HOCH2CH2OH, 13⋅CH3CN, 15⋅H2O, and 16 have been determined by single-crystal X-ray diffraction.