The synthesis and structure of heteroleptic tris(diimine)ruthenium(II) complexes.

The reactions of bidentate diimine ligands (L2) with cationic bis(diimine)[Ru(L)(L1)(CO)Cl]+ complexes (L, L1, L2 are dissimilar diimine ligands), in the presence of trimethylamine-N-oxide (Me3NO) as a decarbonylation reagent, lead to the formation of heteroleptic tris(diimine) ruthenium(II) complexes, [Ru(L)(L1)(L2)]2+. Typically isolated as hexafluorophosphate or perchlorate salts, these complexes were characterised by UV-visible, infrared and mass spectroscopy, cyclic voltammetry, microanalyses and NMR spectroscopy. Single crystal X-ray studies have elucidated the structures of KRu(bpy)(phen)(4,4'-Me(2)bpy)(3).1/2H(2)O, Ru(bpy)(5,6-Me(2)phen)(Hdpa)(2), Ru(bpy)(phen)(5,6-Me(2)phen)(2), Ru(bpy)(5,6'-Me(2)phen)(4,4'-Me(2)bpy)(2).EtOH, Ru(4,4'-Me(2)bpy)(phen)(Hdpa)(2).MeOH and Ru(bpy)(4,4'-Me(2)bpy)(Hdpa)(2).1/2Hdpa (where Hdpa is di(2-pyridyl)amine). A novel feature of the first complex is the presence of a dinuclear anionic adduct, K(2)(PF(6))(6), in which the two potassium centres are bridged by two fluorides from different hexafluorophosphate ions forming a K(2)F(2) bridging unit and by two KFPFK bridging moieties.