Quantum chemical modeling of electron‐deficient hollow TlkPb12–k and TlkBi20–k shells and related endohedral complexes (k = 1; 2)

Abstract The equilibrium structural parameters, symmetry groups, and dipole moments of the free hollow electron‐deficient TlBi 19 , Tl 2 Bi 18 , p ‐, m ‐, o ‐Tl 2 Pb 10 shells and the endohedral (He, Ne)@Tl 2 Pb 10 , (Y, La, Lu, Tl, Bi, Ce)@TlPb 11 , Tl@(Y, La, Lu) Pb 11 , Sr@TlBi 19 , Tl@SrBi 19 , Yb@TlBi 19 , Tl@YbBi 19 , [Y@TlBi 19 ] + , [Lu@TlBi 19 ] + , Sr@Tl 2 Bi 18 , and Yb@Tl 2 Bi 18 complexes are predicted by using DFT (U)PBE0 hybrid method. The isomerization of (Sr, Yb)@Tl k Bi 20–k into Tl@(Sr, Yb) Tl k–1 Bi 20–k is endothermic. The isodesmic substitution of an endo ‐atom in the Tl@TlPb 11 cluster for a rare‐earth atom is exothermic. The hollow Tl k Bi 20–k (Sr, Yb) complexes with Tl in the shell and with Sr or Yb exo ‐atom are impossible. The endo ‐atoms plunge in hollow TlPb 11 and hollow TlBi 19 shells without delay on its surface. The ( C 5v )‐TlPb 11 and ( C 3v )‐TlBi 19 shells are stabilized by an endo ‐atom X with oxidation number Ξ X = +3 and +2, respectively. No one cerium IV oxidation state has been predicted. The integer number Ξ X is presented as a function of the populations of one‐electron states in the shell surrounding the endo ‐atom X. Each Pb or Bi atom in the electron‐deficient clusters retains an entirely localized lone electron pair. The change in the IR spectrum when a metal atom is embedded into its cavity indicates a strong interaction between the components of the endohedral complex. Structural aspects of the β‐decay of a radioactive endo ‐atom in the cavity of a metal cluster are discussed.