High-Pressure Effects in Hydrofullerene C60H36 Studied by Raman Spectroscopy

The effect of hydrostatic pressure on the Raman spectrum of hydrofullerene C60H36, at room temperature has been investigated up to 12 GPa. The samples were synthesized by means of high-pressure hydrogenation. The pressure dependence of the phonon frequencies exhibits two reversible changes one at ∼0.6 GPa and another one at ∼6 GPa. The first may be probably related to a phase transition from the initial orientationally disordered bcc structure to an orientationally ordered one. The second one, at ∼6 GPa, is probably driven by pressure-induced bonding of hydrogen to a carbon atom of a neighboring hydrofullerene cage.