Radical sponge

Xiao L, Takada H, Gan XH, Miwa N (2006) The water-soluble fullerene derivative Radical Sponge exerts cytoprotective action against UVA irradiation but not visible-light-catalyzed cytotoxicity in human skin keratinocytes. Bioorg. Med. Chem. Lett. 16 1590-1595. 

CgQ is a radical sponge (Scheme 14.4) and readily adds organic as well as inorganic radicals (see Chapter 6). As with nucleophilic additions, multiple additions take place if an access of radicals is allowed to react with the fullerene. 

The fullerene skeleton can not only undergo nucleophilic additions, but it also enters into radical reactions very easily. The fullerene acts as a radical sponge in these reactions, and either dia- or paramagnetic derivatives are obtained depending on the number of transferred electrons. 

Fullerenes exhibit strong electron affinity and act as radical sponges. ... 

Generally, the degradation of polymers is thought to be a free radical chain reaction through (3-scission of polymer chains. Ceo, described as a radical sponge [30], has high reactivity toward free radicals, in that it has 30 carbon-carbon double bonds and can trap more than 34 free radicals [30, 36-38], Thus, Ceo can trap the macromolecular or any other radicals created by the pyrolysis of polymers and then form a gelled ball network in situ. The network can increase the melt viscosity and consequently slow the combustion of polymeric materials. Thus, in another sense, Ceo naay be considered to be a gas phase flame retardant. 

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