Charge Makes a Difference: Molecular Ionic Bismuth Compounds

Abstract

Key challenges in modern synthetic chemistry include the design of reliable, selective, and more sustainable synthetic methods, as well as the development of promising candidates for new materials. Molecular bismuth compounds offer valuable opportunities as they show an intriguing spectrum of properties that is yet to be fully exploited: a soft character, a rich coordination chemistry, the availability of a broad variety of oxidation states (at least + V to À I) and formal charges (at least + 3 to À 3) at the Bi atoms, and reversible switching between multiple oxidation states. All this is paired with the status of a non-precious (semiÀ )metal of good availability and a tendency towards low toxicity. Recent findings show that some of these properties only come into reach, or can be substantially optimized, when charged compounds are specifically addressed. In this review, essential contributions to the synthesis, analyses, and utilization of ionic bismuth compounds are highlighted.

[K2(Bi@Pd12@Bi20)]4–: An Endohedral Inorganic Fullerene with Spherical Aromaticity

“…While Zintl detected the potential existence of the Bi 7 3– anion through potentiometric titration experiments in 1932, Bi 2 2– and Bi 4 2– were the largest known bismuth anion clusters for an extended period. − It was not until 2014 that Dehnen and co-workers successfully isolated Bi 11 3– from the solution phase, overcoming this limitation . Currently reported bismuth anion clusters mostly adopt polycyclic structures or only contain small fragments of Bi, such as [Ge 4 Bi 14 ] 4– and [Ga 2 Bi 16 ] 4– with {Bi 7 } fragments. − Despite the existence of some Bi-containing cage-like cationic clusters and ternary anionic clusters, polybismuth clusters with high-symmetry cage-like structures are yet to be synthesized. − …”

Bismuth(III)-Catalyzed Oxidative Cross-Coupling of 3-Hydroxycarbazoles with Arenols under an Oxygen Atmosphere

“…Bismuth (Bi), the 83rd element in the periodic table, is a nontoxic main group metal, despite its location amid toxic heavy metals (Scheme ). It has been used in pharmaceuticals, physical and material science, and other various fields. − Additionally, it has been used in organic chemistry. , Both organic and inorganic Bi­(III) compounds have been widely used as soft Lewis acid catalysts, and Bi­(V) compounds have been applied to stoichiometric oxidative reactions. − However, Bi compounds have rarely been used as redox catalysts . Triphenylbismuth, an organobismuth­(III) compound, behaves as a redox catalyst in the presence of a terminal oxidant in the oxidative cleavage of 1,2-diols and in the oxidation of hydrazones .…”