Mixing solutions of p-tBucalixarene and C60 in toluene results in a 1:1 complex (C60)∩(p-tBu-calix-arene), which precipitates as nanofibers. The principle structural unit is based on a host-guest ball-and-socket nanostructure of the two components, with an extended structure comprising zigzag/helical arrays of fullerenes (powder X-ray diffraction data coupled with molecular modeling). Under argon at temperatures above 309°C, the fibers undergo selective volatilization of the calixarenes to afford C60-core nanostructures encapsulated in a graphitic material sheath, which exhibits a dramatic increase in surface area. Above 650°C the material exhibits an ohmic conductance response, due to the encapsulation process.
- Host-guest systems
- Supramolecular chemistry