Synthesis and structural characterisation of new RuII[12]aneS4 complexes with polypyridylic and related ligands

Abstract

The reaction between cis-[Ru(dmso)Cl₂] (dmso=dimethylsulfoxide) and the macrocycle 1,4,7,10-tetrathiacyclododecane ([12]aneS₄) gives the complex cation [Ru([12]aneS₄)(dmso)Cl]⁺. A new series of Ru^II([12]aneS₄) complexes were obtained by replacing the dmso and the chlorine ligands with polypyridylic or related monodentate ligands. Complexes with the general formula [Ru([12]aneS₄)(L)]²⁺, where L=bidentate ligand: dipyridylamine (dipa); 5-phenyl-1,10-phenanthroline (5-phen); 1,10-phenanthroline-5,6-dione (5,6-dione); o-phenylenediamine (pda) or 4,4′-diphenyl-2,2′-dipyridyl (dbp) have been synthesised. Related complexes containing monodentate ligands, [Ru([12]aneS₄)(CH₃CN)Cl]⁺, [Ru([12]aneS₄)(CH₃CN)₂]²⁺ and [Ru([12]aneS₄)(ind)Cl)]⁺ (ind=indazole) were also prepared. The complexes were characterised by NMR, UV/Vis and IR spectroscopy and their electrochemical behaviour was studied by cyclic voltammetry. The X-ray single crystal diffraction structures of the complexes [Ru([12]aneS₄)(dmso)Cl]Cl, [Ru([12]aneS₄)(CH₃CN)₂][PF₆]₂, [Ru([12]aneS₄)(CH₃CN)Cl]PF₆, [Ru([12]aneS₄)(5,6-dione)][PF₆]₂·2CH₃CN, [Ru([12]aneS₄)(5-phen)][PF₆]₂ and [Ru([12]aneS₄)(ind)Cl]PF₆·CH₃CN were determined. All complexes exhibit a distorted cis-octahedral environment with the macrocycle adopting a folded conformation.