ENDOHEDRAL FORMATION FROM NEUTRON-ACTIVATION OF INTERSTITIAL RARE-GASC-60 FULLERIDES

Rare gas interstitial fullerenes, produced by hot isostatic pressing s olid C-60 in the presence of Ar, Kr or Xe, have been neutron irradiate d and their behaviour investigated. The activity of the generated radi onuclides was found to be in agreement with calculations and this comb ined with X-ray powder diffraction showed that both the activated radi onuclides and the unactivated rare gas remained trapped in the solid a fter they have been subjected to the harsh conditions encountered in a nuclear reactor. Gamma spectroscopy of the irradiated solids and solu tions of them in toluene provided strong evidence for endohedral compo und formation. We estimate 1 - 2% of the activated rare gas atoms, whi ch recoil as a result of prompt gamma emission, end up in the centre o f what is most likely to be the C-60 molecule or some other fullerene derivative. On this basis, we postulate the formation of RN@C-60 where the radionuclide (RN) is Xe-125g, Xe-133g, Xe-135g, Ar-41 or Kr-85m.