Bi₁₆I₄ – A New Bismuth Subiodide: An Analysis of Molecular Packing and Electronic Structures of the Compounds in the Bi_mI₄ (m = 14, 16, 18) Family

Abstract

A new bismuth subiodide Bi 16 I 4 was synthesized by hightemperature synthesis.

The Subbromide Bi5Br4 – On the Existence of a Hidden Phase

“…Bi 5 Br 4 is the bismuth‐richest compound among the bismuth subhalides containing isolated polycations (Bi 6 Br 7 , Bi 6 Cl 7 ,, Bi 7 Cl 10 ). Only subhalides with infinite ribbons of bismuth atoms (BiBr = Bi 4 Br 4 , BiI = Bi 4 I 4 ,, Bi 14 I 4 ,, Bi 16 I 4 ,, Bi 18 I 4 , ) can have similar or even higher bismuth content. In the bismuth‐bromine phase diagram, Bi 5 Br 4 is now the bismuth‐richest known binary phase (Figure ).…”

“…However, as we have shown such a sub-solidus reaction is kinetically hindered and disfavored. In many syntheses targeting BiBr -the latter was recently predicted to be a topological insulator [50] -or even bismuth-richer phases in analogy to Bi m I 4 (m = 14,16,18), [44][45][46][47][48] we never obtained Bi 5 Br 4 (or other Bi m Br 4 with m Ͼ 4). The discovery of this hidden phase as a by-product in a ternary reaction mixture was mere serendipity.…”

Bismuth‐based candidates for topological insulators: Chemistry beyond Bi2Te3

“…These structures are of particular interest for the present overview since a strip geometry of a single bismuth [39] closed paramagnetic, metallic [35] layer has theoretically been predicted to be non-trivial as it shows four edge states that correspond to one Kramers pair of edge states, suggesting Z 2 is odd [17]. As in graphene, theory has considered two types of simple edge shapes (zigzag and armchair) available in bismuth films and has confirmed the QSH phase for both [27].…”

“…Going back to the binary bismuth halogenides one finds two possibilities of a strip termination influencing crucially the conductivity of the compound. Based on this property, compounds have been classed into two series with either semiconducting or metallic properties [34,35]. Ab initio calculations predict that the conductivity type is directly connected to the type of the layer termination by halogenide ions, which is either "open" or "closed" with respect to the honeycomb net of bismuth atoms (Fig.…”

Optimized Synthesis of the Bismuth Subiodides BimI4 (m = 4, 14, 16, 18) and the Electronic Properties of Bi14I4 and Bi18I4

“…In the Bi–Br system, both the cluster compound Bi 6 Br 7 , as well as the monobromide Bi 4 Br 4 , which has a packing of 1 ∞ [Bi 4 Br 4 ] ribbons, exist. Infinite ribbons define the structures of the four subiodides Bi m I 4 with m = 4, 14, 16, and 18 . Thus, the most bismuth‐rich halides are obtained by reacting bismuth with the comparatively weakly oxidizing iodine.…”