Cationic half-sandwich complexes (Rh, Ir, Ru) containing 2-substituted-1,8-naphthyridine chelating ligands: Syntheses, X-ray structure analyses and spectroscopic studies

Reactions of the dinuclear complexes [(η6-arene)Ru(μ-Cl)Cl]2 (arene = C6H6, p-iPrC6H4Me) and [(η5-C5Me5)M(μ-Cl)Cl]2 (M = Rh, Ir) with 2-substituted-1,8-naphthyridine ligands, 2-(2-pyridyl)-1,8-naphthyridine (pyNp), 2-(2-thiazolyl)-1,8-naphthyridine (tzNp) and 2-(2-furyl)-1,8-naphthyridine (fuNp), lead to the formation of the mononuclear cationic complexes [(η6-C6H6)Ru(L)Cl]+ {L = pyNp (1); tzNp (2); fuNp (3)}, [(η6-p-iPrC6H4Me)Ru(L)Cl]+ {L = pyNp (4); tzNp (5); fuNp (6)}, [(η5-C5Me5)Rh(L)Cl]+ {L = pyNp (7); tzNp (8); fuNp (9)} and [(η5-C5Me5)Ir(L)Cl]+ {L = pyNp (10); tzNp (11); fuNp (12)}. All these complexes are isolated as chloro or hexafluorophosphate salts and characterized by IR, NMR, mass spectrometry and UV/Vis spectroscopy. The molecular structures of [1]Cl, [2]PF6, [4]PF6, [5]PF6 and [10]PF6 have been established by single crystal X-ray structure analysis.