Capture endohedral

In this chapter on chemically modified fullerenes, I will discuss only a few representative molecules which incorporate fullerenes, and focus attention on the best-characterized compounds. A comprehensive review of chemical reactions with fullerenes has just been published by Taylor and Walton.[Ta93] It is not appropriate here to attempt a synthesis of the emerging field of the chemical properties of the fullerenes. Covered elsewhere in this book are ioni-cally bonded fullerides, such as the superconductor KsCeo (Chapter IV) and endohedral complexes, in which various atoms are captured inside the hollow carbon shell (Chapter VI). 

As remarked in section 11.8, materials formed from fullerenes are of interest to develop as anodes for rocking chair batteries. We describe here some of the relevant properties, which depend not on endohedral capture, but rather on interstitial storage or reversible intercallation. 

Elegant experiments have shown that endohedral transmutation of an element can take place within the fullerene cage while it is practically unaffected by high-energy neutron capture and )5-emission events. This was carried out on non-radioactive Gd Cg2, which transmutes into Tb Cg2 under neutron irradiation with emission of a -particle [21]. Monoisotopic Ho in macroscopic quantities (mg) of pure samples of Ho Cg2, Ho2 Cg2, or Ho3 Cg2 was also activated with a high neutron flux to produce stable Er [22]. These initial results strongly suggest that endohedral metallofullerenes may find a useful place in nuclear medicine in a way similar to boron neutron capture therapy (BNCT) [23]. 

Usually CID experiments serve to increase the internal energy of the ions, which then fragment. Under certain conditions, however, such collisions may lead not only to dissociation but also to association. Thus collisions of C o with He at high translational energies ( 3 x 10 m s"0 leads to the capture complex CeoHe . This complex survives a neutralization-reionization (NR) experiment, showing that the ionic and neutral complexes have an endohedral structure He Ceo- Complexes... 

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