Isolation, Structure and Electronic Properties of the Heterofullerene Salt K(sub6)C(sub59)N

The synthesis in macroscopic quantities of the first heterofullerene (C59N)2 has given fresh impetus to the search for materials with potentially interesting properties derived from fullerene solids. Here we report the preparation and structural characterization of the first intercalation compound of azafullerene, K6C59N. It is isostructural with K6C60, adopts a body centered cubic structure (a = 11.31 A) and comprises of quasi-spherical monomeric (C59N)6- ions. Density-functional-theory based calculations of the structural and electronic properties confirm the similarity to K6C60 but also suggest a sizable deformation, principally confined in the vicinity of the nitrogen atom, of both the molecular structure and the electron states. These results demonstrate that there exists an intercalation chemistry of azafullerene to be explored, promising a rich family of both n- and p-doped systems with novel conducting and magnetic properties, like their fullerene antecedents.