Fullerenes halogenation reactions

Addition reactions, electron transfer reactions, and reactions involving the opening of the fullerene cage (chemical surgery) have been thoroughly studied on fullerenes. Other reactions such as nucleophilic additions, cycloaddition reactions, free-radical additions, halogenations, hydroxylation, redox reactions, and metal transition complexations have been reported for Cgo as well. Furthermore, fullerenes are easily reduced by electron-rich chemical reagents as well as electrochemically. Their oxidation, however, is considerably more difficult to achieve [17]. Thus, electrochemical measurements showed the formation from the monoanion to the hexaanion [18]. 

Another route to the preparation of Cgo derivatives involves the reaction of a halogen derivative of diethylmalonate in the presence of a strong base with fullerenes, which results in a... 

Figure 15.8 The Bingel reaction for the modification of fullerenes involves the in situ formation of a reactive halogen species in the presence of the strong base DBU. The cyclopropanation product can be used to create many bioconjugates.

In the substrates, special attention has been devoted to zeolites and fullerenes [34, 38, 39, 44], in the reactions to acid-base equilibria and the influence of hardness and softness on both sides of the equilibrium (acidity of carboxylic acids [45], alkyl [46] and halogenated alcohols [47], hydrides [48] and recently hydrofullerenes [49], basicity of amines [50, 51] and proton affinities of amino acids [52]). For reviews of these studies, see [18, 53, 54],... 

Abstract. It has been revealed that carbonic nanomaterials (fullerene, single- and multiwall nanotubes, nanofibers) display high activity at low temperatures (77K) in reactions of chain halogenation (F2, Cl2) with kinetic chain length up to 104 -105. The ESR spectra of active free- radical intermediates were recorded. The presence of vibration bands of C-Cl bonds in products has been indicated by IR method. 

Prior to the development of tether-directed functionalization methods, regioisomerically pure higher adducts of C50 usually were obtained by additions of transition metal complexes [31-33] or radical halogenations [34, 35]. These reactions either occur under thermodynamic control or lead to the precipitation of the least soluble derivative. Iso-merically pure higher adducts of C o sometimes are also readily isolated out of more complex product mixtures [36]. Tether-directed remote functionalization of CgQ allows the construction of fullerene derivatives with addition patterns that are difficult to obtain by thermodynamically or kinetically controlled reactions with free untethered reagents. Since the description of the first such reaction in 1994 [7], which is the subject of Section 7.3.1, an increasing variety of such regioselective functionalization protocols have... 

With the same fullerene-method, a quantitative conversion of methionine to the corresponding sulfoxides was achieved in about 40 s, using low power, white LED illumination. The reaction time is considerably shorter when compared to the batch procedure that requires, for the same process, about 1 h illumination and the use of a 300 W tungsten halogen lamp. This may be due to the narrow channels space in a microreactor, which favors singlet oxygen diffusion, thus determining a faster reaction. 

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