Surface migrations of endohedral Li⁺ on the inner wall of C₆₀

Quasiclassical trajectory calculations are used to study the dynamics of endohedral Li⁺ ion migration along the inner wall of the C₆₀ cage. The migration involves ion hopping (isomerization) from ring to ring via minimum-energy paths. The thermal rate coefficients for five- to six-member ring isomerization, k₅, and for six- to five- and six- to six-member ring isomerization, k₆, are given by the expressions k₅=(4.0×10¹⁴)exp[(-7800 cal)/RT] s^-1 and k₆=(5.6×10¹⁴)exp[(-10 000 cal)/RT] s^-1. The present work establishes that the ion is not static but moves around along the walls of the molecular cage.