Synthesis and characterization of half-sandwich iridium(III) and rhodium(III) complexes bearing organochalcogen ligands

Reactions of [Cp*M(mu-Cl)Cl](2) (M = Ir, Rh; Cp* = eta(5)-pentamethylcyclopentadienyl) with bi- or tri-dentate organochalcogen ligands Mbit (L1), Mbpit (L2), Mbbit (L3) and [Tm-Me] (L4) (Mbit = 1,1'-methylene-bis(3-methyl-imidazole-2-thione); Mbpit = 1,1'-methylene bis (3-iso-propyl-imidazole-2-thione), Mbbit = 1,1'-methylene bis (3-tert-butyl-imidazole-2-thione)) and [Tm-Me] (Tm-Me = tris (2-mercapto-1-methylimidazolyl) borate) result in the formation of the 18-electron half-sandwich complexes [Cp*M(Mbit)Cl]Cl (M = Ir, 1a; M = Rh, 1b), [Cp*M(Mbpit)Cl]Cl (M = Ir, 2a; M = Rh, 2b), [ Cp* M( Mbbit) Cl] Cl (M = Ir, 3a; M = Rh, 3b) and [Cp*M(Tm-Me)]Cl (M = Ir, 4a; M = Rh, 4b), respectively. All complexes have been characterized by elemental analysis, NMR and IR spectra. The molecular structures of 1a, 2b and 4a have been determined by X-ray crystallography. (C) 2009 Elsevier B.V. All rights reserved.