The prolific {ZR₆}X₁₂R and {ZR₆}X₁₀ structure types with isolated endohedrally stabilized (Z) rare-earth metal (R) cluster halide (X) complexes

Comproportionation reactions of rare-earth metal trihalides, RX₃, with the respective R metal in the presence of a transition metal Z, preferably from group 8 through 10, yielded single crystals of 31 {ZR₆}X₁₂R and 22 {ZR₆}X₁₀ type compounds, in most cases for the first time, especially with R = Tb, Dy, Ho, and Er. These are compared with literature entries. The crystal structures are discussed for the equal-atom pair {IrEr₆}I₁₂Er and {IrEr₆}I₁₀. In both cases, {IrEr₆}Iⁱ₁₂I^a₆ cluster complexes are connected via i-i and i-a/a-i bridges, respectively, the {IrEr₆} clusters are isolated. Band structure calculations were carried out on the LMTO-ASA level for a number of {ZY₆}X₁₀ examples; the density of states (DOS) and Crystal Orbital Hamiltonian Populations (COHP) derived therefrom exhibit strong Z-Y and Y-X bonding interactions. Most profitable are X = I and endohedral elements of sixth period atoms, especially Z = Os, Ir. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)