Binuclear iridium complexes containing bridging 1,2-dicarba-closo-dodecaborane-1,2-dichalocogenolato ligands: Molecular structures of the complexes [(CODIr)2(μ2-S2C2(B10H10))] and [(Cp∗Ir)2(μ2-Se2C2(B10H10))]

Four binuclear iridium complexes with a chelating 1,2-dicarba-closo-dodecaborane-1,2-dichalcogenolate ligands [Ir2(COD)2(μ2-E2C2B10H10)] [E = S (3a), Se (3b)] [(Cp∗Ir)2(μ2- E2C2B10H10)] [E = S (5a), Se (5b)] have been synthesized through different method. The formal oxidation state of iridium in complexes 3 and 5 are I and II, respectively, due to the different electron donor coordinated to the iridium center. All four complexes 3a–5b are characterized by IR, 1H, 13C, 11B NMR spectra and elemental analyses. The molecular structures of complex 3a and 5b have been determined by X-ray crystallographic analysis, only 5b shows the metal–metal interaction between the two iridium atoms.