Aggregation behavior and non-covalent functionalization of borofullerenes B28, B38, and B40: A density functional theory investigation

Fullerene-like boron clusters (borofullerenes) are rising stars in the field of cluster chemistry. In this work, density functional theory calculations revealed that the recently reported small borofullerenes B_n (n = 28, 38, and 40) are all highly reactive and tend to form dimers and even trimers spontaneously. In addition, the non-covalent modification of these borofullerenes by various cycloparaphenylene nanorings can form stable host-guest systems with substantial intermolecular charge transfer at both ground and excited states. Our results demonstrate that the borofullerenes are versatile platform for exohedral functionalization, and are very promising candidates for the design of novel nanomaterials with desirable properties.     

Lanthanide metals in the boron cages: Computational prediction of M@Bn (M = Eu,Gd; n = 38, 40)

Endohedral metalloborofullerenes (EMBFs) are novel boron analogues of the famous endohedral metallofullerenes (EMFs). Many EMBFs have been proposed by theoretical calculations thus far. However, in sharp contrast to EMFs, which trap most of the lanthanides with f electrons inside the cages, the corresponding lanthanide‐based EMBFs have never been reported. In this work, the encapsulation of Eu and Gd in the B₃₈ and B₄₀ fullerenes was studied by means of density functional theory calculations. Our results revealed that Gd@B₃₈(⁹A), Eu@B₄₀(⁸B₂), and Gd@B₄₀(⁷A″) all favor the endohedral configuration, and the electronic structures can be described as Gd³⁺@ , Eu²⁺@ , and Gd³⁺@ with jailed f electron spins. The large binding energies and sizable HOMO–LUMO gaps suggest that they may be achieved experimentally. They feature σ and π double aromaticity, and their excellent stabilities were confirmed by the Born–Oppenheimer molecular dynamics simulations. Finally, the infrared and UV/vis spectra were simulated to assist experimental characterization.