The invention relates to a composition that is the reaction of a fullerene containing at least one corrannulene ring structure and Y.sub.2 X.sub.2, wherein Y is Se or S, and X is Cl or Br. Generally, these compounds may be represented by the formula C.sup.f.sub.n X.sub.6 Y.sub.2 or more particularly C.sup.f.sub.n X.sub.5 (YYX). In the formula C.sup.f.sub.n more specifically, is a fullerene having at least one corrannulene ring structure. The compositions may be made by reacting fullerenes with Se.sub.2 X.sub.2 or S.sub.2 X.sub.2 wherein X is Cl or Br, preferably in liquid form and preferably heated for a time sufficient to produce the novel compositions. The compositions may be isolated in crystalline form by precipitation with a solvent such as hexane. In crystalline form the compositions may be represented by the generic formula C.sup.f.sub.n X.sub.8 Y.sub.4, or more particularly, C.sup.f.sub.n X.sub.5 (YYX).mY.sub.2 X.sub.2 because in crystalline form the compositions are typically associated with .mY.sub.2 X.sub.2 molecules wherein m is an integer at least equal to 1. The compositions have utility as crosslinking agents and lubricating oil and polymer additives, particularly as vulcanizing agents.