ABSTRACT
Structures and properties of supramolecular complexes, consisting of lithium or superalkali lithium fluoride clusters Li n F n −1, n = 2 − 4 from one side, and endohedral fullerenes Li@C60 or pristine fullerene C60 on the other side, are presented. The results obtained from the density functional theory (B3LYP-D3) and coupled-cluster (DLPNO-CCSD) calculations show that those complexes are thermodynamically stable. Moreover, these complexes exhibit an attractive net interaction in all cases. As a result of electron transfer from SA to the carbon cage, they are described as supersalts made of superalkali cation and endohedral fullerene anion (SA+[Li+@C60 ·]–) or superalkali cation and fullerene anion (SA+C60–). The partial charges and local energy decomposition (LED) analysis have shown that superalkali does not affect endohedral Li’s position inside the cage, and its partial charge, nor does it alter its interaction with the C60. The QTAIM analysis reveals that ionic closed-shell interactions occur via Li-C bonds. This chapter presents a significant result, that encapsulation of lithium leads to favourable interactions between superalkalis and fullerene, which in turn enhances the stability of the endohedral complexes compared to complexes with pristine fullerene. Furthermore, the stability of complexes decreases when the transfer of electron density from SA to the fullerene cage is reduced.
