Synthesis, spectral and structural studies of water soluble arene ruthenium (II) complexes containing 2,2′-dipyridyl-N-alkylimine ligand

A series of water soluble complexes of general formula [(η6-arene)Ru{(C5H4N)2CNRi}Cl]PF6 have been prepared by the reaction of [{(η6-arene)RuCl2}2] with appropriate 2,2′-dipyridyl-N-alkylimine ligands (dpNRi) in the presence of NH4PF6 (where; R = Me or Et; arene = p-cymene, C6Me6, C6H6). The 2,2′-dipyridyl-N-alkylimine ligands are prepared by reaction of 2,2′-dipyridyl ketone with the corresponding alkylamine. The complexes are readily obtained as air stable yellow to dark brown solids by simple stirring at room temperature. The complexes are isolated as their hexafluorophosphate salts and characterized on the basis of spectroscopic data. The molecular structure of representative complex [(η6-C6Me6)Ru{(C5H4N)2CN–Me}Cl]PF6 has been determined by single crystal X-ray diffraction studies.