Vibrational spectrum ofsin the p-tert-butylcalix[8]arene(1:1scomplex

We report the results of Raman, infrared, and inelastic neutron scattering investigations of the vibrational spectrum of the complex p-tert-butylcalix[8]arene(1:1)fullerene, a system with almost isolated (Formula presented) molecules confined inside neutral cages. All the internal optical-active modes of the (Formula presented) guest have been identified, and further modes which can be attributed to (Formula presented) intramolecular vibrations appear in the neutron scattering function. A comparison with the vibrational spectrum of empty p-tert-butylcalix[8]arene indicates that the host-guest interaction is very weak. As solid-state effects are also practically suppressed, the investigated complex gives the unique opportunity to study almost free fullerene balls confined in the solid state.