Mono and dinuclear complexes of half-sandwich platinum group metals (Ru, Rh and Ir) bearing a flexible pyridyl-thiazole multidentate donor ligand

The mononuclear cationic complexes [(η6-C6H6)RuCl(L)]+ (1), [(η6-p-iPrC6H4Me)RuCl(L)]+ (2), [(η5-C5H5)Ru(PPh3)(L)]+ (3), [(η5-C5Me5)Ru(PPh3)(L)]+ (4), [(η5-C5Me5)RhCl(L)]+ (5), [(η5-C5Me5)IrCl(L)]+ (6) as well as the dinuclear dicationic complexes [{(η6-C6H6)RuCl}2(L)]2+ (7), [{(η6-p-iPrC6H4Me)RuCl}2(L)]2+ (8), [{(η5-C5H5)Ru(PPh3)}2(L)]2+ (9), [{(η5-C5Me5)Ru(PPh3)}2(L)]2+ (10), [{(η5-C5Me5)RhCl}2(L)]2+ (11) and [{(η5-C5Me5)IrCl}2(L)]2+ (12) have been synthesized from 4,4′-bis(2-pyridyl-4-thiazole) (L) and the corresponding complexes [(η6-C6H6)Ru(μ-Cl)Cl]2, [(η6-p-iPrC6H4Me)Ru(μ-Cl)Cl]2, [(η5-C5H5)Ru(PPh3)2Cl)], [(η5-C5Me5)Ru(PPh3)2Cl], [(η5-C5Me5)Rh(μ-Cl)Cl]2 and [(η5-C5Me5)Ir(μ-Cl)Cl]2, respectively. All complexes were isolated as hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV–vis spectroscopy. The X-ray crystal structure analyses of [3]PF6, [5]PF6, [8](PF6)2 and [12](PF6)2 reveal a typical piano-stool geometry around the metal centers with a five-membered metallo-cycle in which 4,4′-bis(2-pyridyl-4-thiazole) acts as a N,N′-chelating ligand.