Sb9

Sb9 is a polyatomic cluster composed of nine antimony atoms. In cluster chemistry and materials science, Sb9 is studied as a representative pnictogen cluster and as a building block for larger polyantimony frameworks. The neutral cluster and its charged derivatives have been reported in both gas-phase experiments and solid-state systems, where Sb9 units can integrate into Zintl-type intermetallics or exist within host matrices.

Structures proposed for Sb9 include distorted ring-like motifs and compact three-dimensional cages. The exact geometry depends on the charge state (neutral, anion Sb9−, or cation Sb9+) and on environmental factors such as ligation or surrounding lattice. Electronic structure analyses show considerable delocalization over the antimony framework, with bonding patterns that differ from those in bulk antimony.

Sb9 has been observed in the laboratory using techniques such as mass spectrometry to detect the clusters and their charge states, and photoelectron spectroscopy to probe their electronic structure. It can be produced by methods like laser ablation of antimony in inert environments and captured in matrix isolation or embedded in solid hosts for study. Complementary computational studies using density functional theory and ab initio methods are employed to predict geometries, energetics, and spectra.

Sb9 is primarily of interest for understanding the bonding in heavier pnictogen clusters and as a potential precursor to larger antimony-containing materials. Related species include smaller Sb_n clusters (n < 9) and other pnictogen clusters, forming part of the broader field of cluster chemistry.