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 tube. 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 calculations. The C59N reorientational activation energy measured below the face centered cubic (fcc) to simple cubic (sc) transition is 2300 K. This value is similar to that of the matrix C-60 molecules, indicating that C59N-C-60 intermolecular interactions are weak.