The boron heterofullerenes C 59B and C 69B: generation, extraction, mass spectrometric and XPS characterization
Boron heterofullerenes can be generated by arc evaporation of doped graphite rods in a modified fullerene reactor. According to mass spectrometric analysis only mono-substituted fullerenes like C 59B, C 69B and higher homologues can be extracted and enriched by the use of pyridine as the solvent. They are strong Lewis acids and undergo a decomposition reaction to boric acid with traces of oxygen. XPS analysis of the extracts reveals the boron in the fullerene cage to be in a higher oxidation state compared to ordinary boron-carbon compounds. The synthesis and extraction procedure opens a viable route for the macroscopic production of these compounds.