`Nitrogen doped' C60 dimers (N@C60–C60)

Abstract The formation of C 60 dimers with a nitrogen atom in one of the C 60 cages is studied. The dimers are produced by ball milling of a mixture of N@C 60 with C 60 and a suitable additive. The products are purified by high pressure liquid chromatography (HPLC) and identified by UV/Vis and IR spectroscopy. Electron paramagnetic resonance (EPR) measurements show that nitrogen remains in C 60 during the dimerization and keeps its atomic configuration. A slight deformation of the electron shell reflecting the distortion of the cage is observed. The optimization of the dimer formation is described.