Iodine, tellurium, and xenon inside fullerene: modeling of endohedral structures

Abstract

The structural parameters, spin states, quadrupole or dipole moments, embedding energies, and IR spectra of endohedral I⁻@C₆₀, I⁻@C₆₀⁺, I^–@C₅₈B₂, I⁻@[C₅₈B₂]⁺, I⁻@[C₅₉B]⁺, I⁻@[C₆₀I]⁺, (I⁻@C₆₀⁺)₂, Te@C₆₀, Te@C₅₈B₂, Xe@C₆₀, and Xe@C₅₈B₂ complexes are predicted by quantum chemical DFT (U)PBE0 method. The nucleus of an endo-atom is localized in the vicinity of cage center. The distortion of the fullerene structure by the endo-atom is small. The electrically neutral complexes are metastable. The energies of I⁻@C₆₀ and I⁻@C₅₈B₂ anions are lower than the sum of the energies of free components. The addition of the iodine exo-atom to the I⁻@C₆₀⁺ free radical transforms it into the stable singlet I⁻@[C₆₀I]⁺ zwitter-ion, the energy of which is lower than the energy of the molecule C₆₀I₂. The relaxation effect after β⁻ decay of the radioiodide endo-anion in the fullerene cage is very small. The possibilities of synthesis of fullerene and heterofullerene endohedral complexes with radioactive iodine from a tellurium-containing precursor are discussed.

Graphical abstract

X@C_60–kB_k; I@C₆₀I; (I@C₆₀)₂; k = 0, 1, 2; X = I, Te, Xe