Azafullerene C59N, a stable free radical substituent in crystalline C-60

Solid solutions of C59N azafullerene in C-60 with concentrations of 10(-5) to 10(-4) were produced in large quantities in an electric gas discharge tu be. C59N is a stable monomeric substituent molecule in crystalline C-60 The isotropic N-14 and (13) hyperfine coupling constants measured by electron spin resonance (ESR) are characteristic of the extent of delocalization of the charge over the cage and are a sensitive test of electronic structure c alculations. The C59N reorientational activation energy measured below the face centered cubic (fcc) to simple cubic (sc) transition is 2300 K. This v alue is similar to that of the matrix C-60 molecules, indicating that C59N- C-60 intermolecular interactions are weak. (C) 2001 Elsevier Science B.V. A ll rights reserved.