A Bismuth‐Stabilized Metal‐Rich Telluride Lu₉Bi_≈1.0Te_≈1.0 – Synthesis and Characterization

Abstract

Synthetic reactions aimed at bismuth incorporation into rareearth-metal-rich tellurides yielded Lu 9 Bi ≈1.00 Te ≈1.00 over a small range of compositions, but no analogues with Gd, Tb, Er, or Y. A single-crystal X-ray diffraction analysis gave the composition Lu 9 Bi 0.99(3) Te 1.01 in the acentric orthorhombic space group Cmc2 1 at ambient temperature. This is isostructural with the re-refined Sc 9 Te 2 earlier reported in a monoclinic Cc structure. Lu 9 Bi ≈1.00 Te ≈1.00 represents the first ternary compound in this structure type and the third lutetiumrichest compound after Lu 8 Te and Lu 7 Te. The structure contains 3 ϫ 3 columns of Lu in the form of condensed distorted trans-edge-sharing octahedral chains along a. The Te and Bi anions lie within tricapped trigonal prisms of Lu. Generally

Synthesis, Structure, and Bonding of Orthorhombic R5Au2Te2 (R = Lu, Ho, Dy, Y). Electronic Structure of the Binary Parent Valence Compound Eu5As4

“…These reflect the topping up of all Au valence orbitals and the substantial reduction of Au; the same condition applies to basically filled Te 5p states, and both lead to the substantial oxidation of Lu as reflected in the high fraction of the least penetrating Lu 5d states that lie above Fermi. These are common characteristics of many other related metal-rich compounds. ,, (On the other hand, the conclusions are in opposition to a common misinterpretation of stick drawings like Figures and : that the many Lu–Lu connections reflect major bonding in the compound, not just geometric tie-lines …”

“…These are common characteristics of many other related metalrich compounds. 3,17,39 (On the other hand, the conclusions are in opposition to a common misinterpretation of stick drawings like Figures 2 and 3: that the many LuÀLu connections reflect major bonding in the compound, not just geometric tie-lines. 40 ) Some features in the ÀCOHP results can be associated with specific bonding interactions.…”

“…In terms of Hamilton bond populations, the substantial polar LuÀAu and LuÀTe interactions in Lu 5 Au 2 Te 2 are more or less frequent and important characteristics, and in other related metal-rich compounds too. 17,39 This different chemistry clearly removes the gold tellurides from a close relationship with Sm 5 Ge 4 -type phases, and the unlikelihood of Te 2 species, from any comparison with Gd 5 Si 4 , and so on.…”