Molecular Motion of Endohedral Fullerenes in Single‐Walled Carbon Nanotubes

Abstract

Ce-containing endohedral fullerenes were produced by the so-called reversed arc technique developed by the Nagoya group as described previously. 1 A Ce-doped graphite rod (anode) was kept a few mm apart from a graphite block (cathode) in a vacuum chamber. The rod and the block were connected to an external power supply and high current was passed through them (300 – 500 A). The vaporisation took place in He atmosphere (50 – 100 Torr). The resulting soot contained 10 – 20 % fullerenes. The fullerenes were soxhlet-extracted from the soot for ca. 4 hours in o-xylene. A two-stage high performance liquid chromatography (HPLC) method was employed to isolate individual fullerene isomers. In the first stage, the o-xylene solution was passed through a Cosmosil 5PBB column (20 ° 250 mm, Nacalai Tesque) with o-xylene eluent (flow rate: 11 ml/min). Figure 1 shows the HPLC chromatogram of Ce-containing endohedral fullerenes. Figure 1. A HPLC chromatogram of Ce-containing endohedral fullerenes. The main diagram shows the first stage separation and, the inset shows the second (recycling) stage of