Excited-state decay dynamics of endohedral metal-metal-bonding fullerenes.

Endohedral metal-metal-bonding fullerenes, in which the endohedral metal atoms form covalent metal-metal bonds, are typical models for studying the confined metal-metal bonds. Herein, utilizing time-dependent ab initio nonadiabatic dynamic simulations, we explore the electron excited-state decay dynamics in endohedral metal-metal-bonding fullerenes M2@C82 (M = Sc, Y, La). The calculation results revealed that the electron relaxation time decreases with initial excited energy, with saturation occurring for excess energies starting from 2.1 eV. Y2@C82 exhibits a significantly longer electron decay time compared to Sc2@C82 and La2@C82. The reasons are attributed to the unique electronic structure and dynamics associated with the Y atoms, which modify the density of states and impact motion. Those findings enhance our understanding of the intricate dynamics within endohedral fullerenes and highlight the importance of metal elements in tailoring their physical properties for advanced applications.