The synthesis of heteronuclear clusters containing cyclopentadienyl- or pentamethylcyclopentadienyliridium and ruthenium or osmium

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp∗)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp∗(μ-OH)(CO)10Cl] (2), [Os3IrCp∗(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp∗(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

“…The valence electron count of this structure is 76, which is 2 electrons less than the prediction by the effective atomic number (EAN) rule. The average Ir-Os bond length observed in 1 is 2.802 Å , and is within the reported range of a typical Ir-Os bond (2.70-2.95 Å ) [10][11][12][13]. The Ir(1) atom, however, does not lie on the same plane as the Os 3 triangular face, but at a distance of 1.002(1) Å above the plane.…”

“…The Ir-Os bond length observed in 3 is 2.7760(5) Å , and is shorter than our prediction as it is bridged by a bulky chloride atom. The average Os-Os bond is 2.8797 Å , which falls within the range of a typical Os-Os bond [Os 3 (CO) 12 2.877(3) Å ] [19]. A hydride signal was observed in the 1 H NMR spectrum, and is located at the Os(1)-Os(2) edge as it has a longer bond length (2.9578(4) Å ) than the other Os-Os edges, and falls within the range of hydride-bridged Os-Os bonds.…”

“…The two carbonyl groups bridge the Ir(2)-Os(3) edge asymmetrically, with an average Ir(2)-C and Os(3)-C bond length of 2.135 Å and 1.985 Å , respectively. The difference in the bond lengths does not arise from the difference in metal radii, as the bond length of M-C in [Ir 4 (CO) 12 ] and [Os 3 (CO) 12 ] is 1.874 and 1.978 Å , respectively [19,20]. This structure is unique because this kind of metal-metal bond bridged by two carbonyl ligands on the same plane has not been reported in any osmium mixed-metal cluster.…”

“…However, only a few studies have been published concerning this type of system in osmium-iridium mixed-metal clusters. The clusters can be prepared from the reaction of triosmium clusters and mononuclear iridium complexes that contain either Cp or Cp * [11][12][13][14][15][16][17][18]. Herein, we report the reaction of [Os 3 (CO) 10 (MeCN) 2 ] with [IrCp * Cl 2 ] 2 in refluxing dichloromethane, which gave rise to two new osmium-iridium mixed-metal clusters.…”

Reactivity of the Unsaturated Hydride [Mo2(η5-C5H5)2(μ-H)(μ-PCy2)(CO)2] toward 17- and 16-Electron Metal Carbonyl Fragments: Rational Synthesis of Electron-Deficient Heterometallic Clusters

“…Extensive studies have also been carried out with the isoelectronic dirhenium complex [Re 2 (μ-H) 2 (CO) 8 ], which reacts easily with different transition-metal complexes such as the metal carbonyl anions [M(CO) x ] - (M = Mn, Re, Ir; x = 4, 5) and [Re 2 H(CO) 9 ] - 8a,9 or the neutral late transition-metal compounds [Pt(PPh 3 ) 2 (C 2 H 4 )], [Pt(COD) 2 ], or [Ir(CO)(η 5 -C 9 H 7 )(η 2 -C 8 H 14 )], to give new tri- or tetranuclear clusters. Finally, the reactivity of the triosmium dihydride [Os 3 (μ-H) 2 (CO) 10 ] toward organometallic fragments has been also widely studied, allowing the synthesis of heterometallic clusters with higher nuclearity and incorporating transition-metal atoms from groups 6, , 8, − 9, − 10, 19a, 11, 19a, and 12 …”