Polystyrene hexa-adducts of higher fullerenes

Polystyryl-lithium of low polydispersity has been reacted with C-60, C-70, C-84 and C-96 in a non-polar solvent. Star-shaped polymers were always obta ined and in all cases the maximum number of grafts attached to the fulleren e was found to be 6. This upper limit is a consequence of the fact that the number of pentagons stays constant whatever is the size of the fullerene. In order to get the needed reactive double bond, the pentagones have to for m a pyracyclene unit (2 pentagons and 2 hexagons). The number of pentagons being always 12, no more than 6 chains can be grafted on a fullerene by thi s kind of chemistry.