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Schlagwörter:
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Zusammenfassung:
Crystals of Bi4Ir, a new intermetallic compound, were obtained by the
reaction of an iridium-containing intermetallic precursor with liquid
bismuth. X-ray diffraction on a single crystal revealed a rhombohedral
structure [R (3) over barm, a = 2656.7(2) pm, and c = 701.6(4) pm].
Bi4Ir is not isostructural to Bi4Rh but combines motifs of the
metastable superconductor Bi14Rh3 with those found in the weak
topological insulator Bi14Rh3I9. The two crystallographically
independent iridium sites in Bi4Ir have square-prismatic and
skewed-square-antiprismatic bismuth coordination with Bi-Ir distances of
283-287 pm. By sharing common edges, the two types of [IrBi8] units
constitute a complex three-dimensional network of rings and helices. The
bonding in the heterometallic framework is dominated by pairwise Bi-Ir
interactions. In addition, three-center bonds are found in the bismuth
triangles formed by adjacent [IrBi8] polyhedra. Density functional
theory based band-structure calculations suggest metallic properties.
