'Nitrogen doped' C-60 dimers (N@C-60-C-60)

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 pressu re liquid chromatography (HPLC) and identified by UV/Vis and IR spectroscop y. Electron paramagnetic resonance (EPR) measurements show that nitrogen re mains in C60 during the dimerization and keeps its atomic configuration. A slight deformation of the electron shell reflecting the distortion of the c age is observed. The optimization of the dimer formation is described. (C) 2001 Elsevier Science B.V. All rights reserved.