Strong Binding of Noble Gases to [B12X11]˗: A Theoretical Study

We systematically explore the stability and properties of [B₁₂X₁₁Ng]⁻ adducts resulting from the capture reaction of noble gas atoms (Ng) by anionic [B₁₂X₁₁]⁻ clusters in the ion trap. [B₁₂X₁₁]⁻ can be obtained by stripping one X⁻ ligand off the icosahedral closo-dodecaborate dianion [B₁₂X₁₂]²⁻. We study the binding of the noble gas atoms He, Ne, Kr, Ar and Xe to [B₁₂X₁₁]⁻ with ligands X = F, Cl, Br, I, CN. While He cannot be captured by these clusters and Ne only binds at low temperatures, the complexes with the heavier Kr, Ar and Xe show appreciable complexation energies and exceed 1 eV at room temperature in the case of [B₁₂(CN)₁₁Xe]⁻. For the latter three noble gases, we observe a significant charge transfer from the Ng to the icosahedral B₁₂ cage.