Iridium-Germanium and - Tin Carbonyl Complexes

The new compound Ir(COD)(CO)(2)GePh3, 1, was obtained when a solution containing [Ir(COD)Cl](2) and HGePh3 was treated with a solution of BuLi under a purge with CO. The tin homologue Ir(COD)(CO)(2)SnPh3, 2, was obtained similarly by replacing the HGePh3 reagent with HSnPh3. The reaction of [Ir(COD)Cl](2) with HGePh3 and CO in the absence of BuLi yielded the compound HIr(CO)(3)(GePh3)(2), 3. When 3 was heated to reflux in toluene solvent, three new compounds were formed: Ir-2(CO)(6)(GePh3)(2)(mu-GePh2), 4; H2Ir2(CO)(4)(GePh3)(2)(mu-GePh2)(2), 5; and Ir2(CO)8[mu-Ph2Ge(OH)GePh2](mu-GePh2)(GePh3)(2)(mu-H), 6. The yield of 5 was increased when the reaction was performed under an atmosphere of hydrogen, and the yield of 4 was increased when the reaction was performed under an atmosphere of CO. The reaction of 4 with H2GePh2 yielded 5, 6, and the new compound H2Ir2(CO)(4)(mu-GePh2)(GePh2H)(2), 7. Compounds 1-7 were fully characterized by IR, H-1 NMR, and single-crystal X-ray diffraction analyses. Molecular orbital calculations on compounds 5 and 7 were performed and compared.