Approaches to trinuclear half-sandwich carbene complexes containing 1,2-dicarba-closo-dodecaboranes

Abstract

The synthesis of trinuclear half-sandwich iridium and rhodium complexes containing both N-heterocyclic carbene (NHC) and 1,2-dicarba-closo-dodecaborane ligands is described. Complexes {Cp*M[E₂C₂(B₁₀H₁₀)]}₃(L) (Cp* = pentamethylcyclopentadienyl; L = tris(2-(3-methylimidazol-2-ylidene)ethyl)amine; M = Ir (7), Rh (8); E = S (a), Se (b)) were obtained from the reactions of Cp*M[E₂C₂(B₁₀H₁₀)] (M = Ir (3), Rh (4)) with a silver-NHC precursor or from the reactions of [Cp*MCl₂]₃(L) (M = Ir (5), Rh (6)) with Li₂E₂C₂(B₁₀H₁₀) (E = S, Se). The complexes were characterized by IR, NMR spectroscopy, elemental analysis. In addition, X-ray structure analyses were performed on complexes 7a and 8b.