Synthesis, Spectroscopic and Molecular Studies of Half‐Sandwich η6‐Arene Ruthenium, Cp* Rhodium and Cp* Iridium Metal Complexes with Bidentate Ligands

Abstract

AbstractThe bidentate ligand benzoyl(2‐pyridyl)thiourea (L1) was prepared by reaction of benzoyl isothiocyanate with primary amine (2‐aminopyridine) but the reaction with secondary amine bis(2‐pyridyl)amine, yielded the unexpected product bis(2‐pyridyl)benzoylamine (L2). Mononuclear complexes of the general formula [(η6‐arene)Ru(L)Cl]+ {where, L = L1, arene = benzene (1); p‐cymene (2); L = L2, arene = benzene (5); p‐cymene (6)} and [Cp*M(L)Cl]+ {where, L = L1, M = Rh (3), Ir (4); L = L2, M = Rh (7), Ir (8)}, respectively, were formed by reaction of the ligands L1 and L2 with precursor complexes [(η6‐arene)Ru(μ‐Cl)Cl]2 and [Cp*M(μ‐Cl)Cl]2 (M = Rh, Ir). The cationic complexes were characterized by FT‐IR, UV/Vis, and 1H‐NMR spectroscopy as well as mass spectrometry. X‐ray crystallographic studies of these complexes reveal piano‐stool‐like arrangements around the metal atoms with six‐membered metallacycles in which L1 and L2 act as a N, S‐ and N, N' chelating ligands, respectively.