A Topological Link between Lanthanide and Alkali‐Metal Clusters: Face‐Sharing Gadolinium Octahedra Centered by Endohedral Iridium Atoms in {Ir₃Gd₁₁}Br₁₅

Abstract

The oligomeric cluster complex {Ir3Gd11}Br15 was first obtained from a reaction of Gd, GdBr3 and Ir in a 3:4:1 molar ratio at 1123 K. The crystals belong to the hexagonal space group P63/m with lattice parameters a = 1276.79(14) pm and c = 1286.92(16) pm. The structure features isolated {Ir3Gd11} cluster trimers, which are built up by three face‐sharing gadolinium octahedra each centered by an iridium atom. The endohedral iridium atoms form a triangle with Ir–Ir distances of 295.51(11) pm. Thus, the {Ir3Gd11} cluster is topologically equivalent to the suboxide {O3Cs11}. The {Ir3Gd11} clusters are encapsulated in a coordination sphere of 30 bromide ions, which act as bridging ligands according to the formulation {Ir3Gd11}Bri–i12/2Bri–a9/2Bra–i9/2. In {Ir3Gd11}Br15 there are 45 electrons present for intracluster bonding.

Condensed Double‐Chain Cluster Complexes with Seven‐Coordinate Endohedral Iridium Atoms in {Ir2Gd5}Br5

“…[6] The system Ir/Gd/Br appears to be rich of compounds: So far we have grown crystals and determined the crystal structures of {IrGd 6 }Br 10 (X/R = 1.67; isolated octahedra) [7] and {Ir 3 Gd 11 }Br 15 (X/R = 1.36; trimer of octahedra sharing edges). [8] We now add {Ir 2 Gd 5 }Br 5 (X/R = 1), which is, to date, the most condensed cluster compound within the Ir/Gd/Br system. of gadolinium atoms with endohedral iridium atoms are connected by common rectangular faces to chains and further by edges to double chains, which form a herringbone arrangement.…”