Structural characterisation of new RuII[9]aneS3 polypyridylic complexes

Abstract

A large number of new [Ru^II([9]aneS₃)(L)Cl]⁺ complexes (where L is a polypyridyl bidentate ligand) were synthesized from the precursor [Ru([9]aneS₃)(dmso)Cl₂] in the search for new DNA intercalators. The ancillary ligands used have different molecular architectures which include cross bridges, pyridyl units, phenanthroline and diamine derivatives. The related complex [Ru([9]aneS₃)(ind)Cl₂], containing the monodentate ligand indazole, was also prepared. The diimine complexes [Ru([9]aneS₃)(pdi)Cl]⁺ and [Ru([9]aneS₃)(phi)Cl]⁺ were prepared in situ from the ligands pda (o-phenylenediamine) and dap (phenanthrene-9,10-diamine), respectively, via Ru assisted amine/imine oxidation. All complexes were characterised through ¹H NMR, IR, UV-Vis and electrospray mass spectrometry. Furthermore, the PF₆ salts of seven [Ru([9]aneS₃)(L)Cl]⁺ and [Ru([9]aneS₃)(dip)Cl]BF₄ (dip = 4,7-diphenylphenanthroline) have been investigated by X-ray single crystal diffraction. The crystal structures are presented and analysed in terms of the molecular assemblies of the complex cations and anions and the molecular hydrogen bonding interactions. The π-stacking geometric arrangements of the extended aromatic systems dppz (dipyrido[3,2-a∶2′,3′-c]phenazine) and dip in their metal complexes are also discussed.