Study of half-sandwich platinum group metal complexes bearing dpt-NH2 ligand

Abstract

Abstract A quite general approach for the preparation of η5-and η6-cyclichydrocarbon platinum group metal complexes is reported. The dinuclear arene ruthenium complexes [(η6-arene)Ru(μ-Cl)Cl]2 (arene = C6H6, C10H14 and C6Me6) and η5-pentamethylcyclopentadienyl rhodium and iridium complexes [(η6-C5Me5)M(μ-Cl)Cl]2 (M = Rh, Ir) react with 2 equiv. of 4-amino-3,5-di-pyridyltriazole (dpt-NH2) in presence of NH4PF6 to afford the corresponding mononuclear complexes of the type [(η6-arene)Ru(dpt-NH2)Cl]PF6 {arene = C10H14 (1), C6H6 (2) and C6Me6 (3)} and [(η6-C5Me5)M(dpt-NH2)Cl]PF6 {M = Rh (4), Ir (5)}. However, the mononuclear η5-cyclopentadienyl analogues such as [(η5-C5H5)Ru(PPh3)2Cl], [(η5-C5H5)Os(PPh3)2Br], [(η5-C5Me5)Ru(PPh3)2Cl] and [(η5-C9H7)Ru(PPh3)2Cl] complexes react in presence of 1 equiv. of dpt-NH2 and 1 equiv. of NH4PF6 in methanol yielded mononuclear complexes [(η5-C5H5)Ru(PPh3)(dpt-NH2)]PF6 (6), [(η5-C5H5)Os(PPh3)(dpt-NH2)]PF6 (7), [(η5-C5Me5)Ru(PPh3)(dpt-NH2)]PF6 (8) and [(η5-C9H7)Ru(PPh3)(dpt-NH2)]PF6 (9), respectively. These compounds have been totally characterized by IR, NMR and mass spectrometry. The molecular structures of 4 and 6 have been established by single crystal X-ray diffraction and some of the representative complexes have also been studied by UV–Vis spectroscopy.