A Series of Endohedral Metallo-BN Fullerene Superatomic Structures.

ABSTRACT

Superatoms are crucial in the assembly of functional and optoelectronic materials. This study investigates the endohedral metallo-boron nitride [boron nitride (BN)] fullerenes U@B12N12, Cm@B12N12, and U@B16N16 in theory. Our findings confirm that U@B12N12, Cm@B12N12, and U@B16N16 are superatoms and their electronic configurations are 1P61S21D101F142P62S22D102F123P6, 1P61S21D101F141G161H162S22P62D102F12, and 1P61S21D101F142P62S22D102F14, respectively. Notably, the orbital energy levels in these superatoms exhibit a flipping phenomenon, deviating from those of previous superatom studies. Further, the orbital composition analyses reveal that superatomic orbitals 1S, 1P, 1D, and 1F mainly originate from BN cages, whereas the 2S, 2P, 2D, 2F, and 3P superatomic orbitals arise from hybridizations between BN cage orbitals and the 7s, 7p, 6d, and 5f orbitals of actinide atoms. And the energy gap of endohedral metallo-BN fullerene superatoms is reduced by introducing actinide atoms. Additionally, the analyses of ionization potentials and electron affinities show that U@B12N12, Cm@B12N12, and U@B16N16 have lower ionization potentials and higher electron affinities, suggesting decreased stability compared to that of pure BN cages. This instability may be linked to the observed flipping of the superatomic orbital energy levels. These insights introduce new members to the superatom family and offer new building blocks for the design of nanoscale materials with tailored properties.