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

Abstract The 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 [(η 6 ‐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 [(η 6 ‐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 1 H‐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.