Theoretical investigation of equilibrium and transition state structures, binding energies and barrier heights of water-encapsulated open-cage [59] fullerenone complexes

摘要

The encapsulation of a water molecule within two open-cage [59] fullerenones with 18-membered-ring (1) or 19-membered-ring orifices (2) is studied by DFT with empirical dispersion terms. The equilibrium structure of each H2O@[59]fullerenone and the transition-state structure for the water molecule leaving the cage are optimised and the counterpoise-corrected binding energy and barrier height are calculated. While the H2O binding energies in H2O@ 1 and H2O@ 2 are almost equal, the barrier for H2O leaving the cage is much higher for 1 (108 kJ mol (1)) than for 2 (46 kJ mol (1)). A water molecule can enter the cage-opened fullerenone 2 almost barrierless, whereas this barrier is 63 kJ mol (1) in 1.