Langmuir films of calix[8]arene fullerene complexes

We present the pressure area isotherms for Langmuir films made of calix[8]arene, the calix[8]arene/C-60 complex, and the calix[8]arene/C-70 complex, all of them measured at 306.1 K. A Brewster angle microscope was used to observe the phases shown by the pi-A isotherms. In these three cases, we found a solid phase and its solid-gas coexistence but no expanded liquid phases. The Langmuir films made of calix[8]arene and the calix[8]arene/C-60 complex are very similar. The experimental information is consistent with the assumption that C-60 is situated inside the cavity of calix[8]arene. The Langmuir films of calix[8]arene and the calix[8]arene/C-70 complex are not very similar; we present a discussion to explain the origin of this difference.