Expansion of orifices of open C60 derivatives and formation of an open C59S derivative by reaction with sulfur.

The reaction of a tetraketo-open-cage C60 derivative with elemental sulfur in the presence of tetrakis(dimethylamino)ethylene afforded novel open C60 derivatives containing sulfur atom(s) in the rim of the orifice and the first example of an open C59S derivative. The single crystal X-ray analyses clearly determined these structures and demonstrated that a water molecule was encapsulated inside the cages. The orifice sizes and electronic properties of these fullerene derivatives were revealed.