Probing the Structure-Property Relationships of Na⁺···Cl^-@C₅₀N₅H₅ under the External Electric Field

Endohedral open-cage fullerenes are one of the attractive types of fullerenes due to their interesting electronic properties which make it potentially promising for applications in molecular electronics. In this paper, a novel structure of Na⁺···Cl^-@C₅₀N₅H₅ with Na⁺ inside the cavity and Cl^- at the opening of the open-cage fullerene is designed to explore the chemical bonding and interaction between the open-cage fullerene system C₅₀N₅H₅ and NaCl salt. Further, the directional migration of Na⁺ was achieved by applying an external electric field (EEF) along the X-axis. Notably, when the EEF ranges from -85 to -86 × 10^-4 au, Na⁺ sharply approaches Cl^- to regain its ionic bonding character. In addition, the Wiberg bond index, electron localization function topological analysis, and interaction energy (E_int) of the structure under the effect of the EEF also experienced a series of interesting changes. We hope that this work will provide a new strategy for the design of innovative materials for molecular electronics.