Vibrational spectrum of C60 in the p-tert-butylcalix+8?arene,,1:1...C60 complex

We report the results of Raman, infrared, and inelastic neutron scattering investigations of the vibrational spectrum of the complex p-tert-butylcalix8arene1:1fullerene, a system with almost isolated C60 molecules confined inside neutral cages. All the internal optical-active modes of the C60 guest have been identified, and further modes which can be attributed to C60 intramolecular vibrations appear in the neutron scattering function. A comparison with the vibrational spectrum of empty p-tert-butylcalix8arene indicates that the hostguest 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.