Higher fullerenes hydrogenation

Ceo and higher fullerenes are distinguished from other allotropes of carbon, diamond and graphite, in that they exist as discrete molecules. The spherical or ellipsoidal nature of the monotropes opens up the possibility of intriguing new areas of chemistry. Here we are only interested in the hydrogen (or muonium) adducts, although this study has important implications to the very vigorous and extensive research in fullerene chemistry. 

Finally, it may be mentioned that product mixtures from ozonation,292 hydrogenation,283 and methylenation293 of higher fullerenes have been reported. 

Apart from these, a number of reactions, e.g. ozonation [150], hydrogenation [151], fluorination [152], and the formation of methylene adducts by reaction with THF [153], have led to various mixtures of higher fullerene derivatives. Finally, as the methods for production and purification of endohedral fullerene derivatives are being improved, the exohedral functionalization of Qq [70, 73, 74] and C70 [73] cages containing noble gas atoms, and of endohedral metallo-fullerenes [64,154] emerge as new fields of fullerene chemistry. 

Fullerene showed antibacterial activity, which can be attributed to different interactions of C60 with biomolecules (Da Ros et al., 1996). In fact, there is a possibility to induce cell membrane disruption. The fullerene sphere seems not really adaptable to planar cellular surface, but for sure the hydrophobic surface can easily interact with membrane lipids and intercalate into them. However, it has been demonstrated that fullerene derivatives can inhibit bacterial growth by unpairing the respiratory chain. There is, first, a decrease of oxygen uptake at low fullerene derivative concentration, and then an increase of oxygen uptake, which is followed by an enhancement of hydrogen peroxide production. The higher concentration of C60 seems to produce an electron leak from the bacterial respiratory chain (Mashino et al., 2003). 

Higher degrees of hydrogenation require formal 1,2-additions. The polyhydro-fullerene formed by the complete and exclusive 1,4-addition mode is rjj-C5(,H24 (Figure 5.9). 

Putting any of the 36 hydrogens inside the fullerene leads to conformers with higher energies [76]. 

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