Fullerenes introduction

Alternative strategies utilizing the initial introduction of suitable chemical functionality onto the fullerene have been adopted by several research groups, allowing conjugation of the saccharides with complementary functions in the final synthetic steps. This approach has led to improved flexibility with the chemical functions on the carbohydrate moieties, especially the anchoring ones, and a better control on the number of attached saccharide residues. 

Water colloid solutions of fullerenes C60 (10 4 M) were prepared as described in Scharff et al. (2004). Fullerene-aminopropylaerosyl (fullerene C60-composite-l) was synthesized (Golub et al., 2003) by the introduction of aminopropyl chains oriented ad extra by amine groups (0.9 mM/g), to the surface layer of sihcon dioxide nanoparticles that were bound to fullerene C60 (0.12 mM/g) (Fig. 6.1). Fullerene-anthracenaliminopropylaerosyl (fullerene C60-composite-2) was composed also from anthraccnaliminc (0.2mM/g) that was introduced via azomethine condensation of aldehyde group of anthracenal with surface amino group. 

So, in this work it has been shown that after irradiation of 10 5 M fullerene C60 and fullerene C60-containing composites (A- = 320-580 nm) in aqueous solutions and cell suspensions, the generation of reactive oxygen species is observed, and the rate of their generation increases in the case of introduction of fullerenes C60 to the content of aminopropylaerosyl and anthracenaliminopropylaerosyl. 

The introduction of two [5,6]-aza bridges shows a remarkable regioselectivity even if segregated alkylazides are used [17]. The diazabishomofullerenes 23 (Scheme 10.3) are by far the major products and only traces of one other bisadduct with unidentified structure are found if, for example, a twofold excess of azide is allowed to react with CgQ at elevated temperatures [17]. To obtain clues on the mechanism of this most regioselective bisadduct formation process in fullerene chemistry a concentrated solution of an azahomofullerene precursor 24 was treated with an alkyl azide at room temperature. 

In analogy to olefins, Cjq undergoes a broad variety of cycloadditions (see Chapter 4 and Scheme 14.3). In many cases cycloadducts of Cjq exhibit the same stability as the corresponding non-fullerene based adducts. These reactions are very useful for the introduction of fimctionat groups. Among the most important cycloadditions are [4-1-2] cycloadditions such as Diels-Alder and hetero-Diels-Alder reactions, where Cjq reacts always as dienophile, [3-1-2] cycloadditions with 1,3 dipoles, thermal or photochemical [2-1-2] cycloadditions, [2-t-l] cycloadditions and others, for example, [8-1-2] cycloadditions. Among these general reactions several examples deserve special attention, since they reflect characteristic chemical properties of Cjq [36] ... 

It is therefore useful to look at a l,2-dihydro[60]fullerene as a stereoelectronically slightly perturbed Cjq. Introduction of a double bond into a five-membered ring costs about S.Skcalmol (Figure 14.10) [111]. In a 1,4-adduct (l,4-dihydro[60]-fullerene) one, and in a 1,6-adduct (l,16-dihydro[60]fullerene or 1,6- dihydro[60]-fuUerene) two, double bonds in five-membered rings are required for the corresponding lowest-energy Kekule structure. This VB consideration is also confirmed experimentally and by computations (Figure 14.8) [36],... 

Wang T, Chen N, Xiang J et al (2009) Russian-doll-type metal carbide endofullerene synthesis, isolation, and characterization of Sc4C2 Cgo. J Am Chem Soc 131 16646-16647 Chen N, Chaur MN, Moore C et al (2010) Synthesis of a new endohedral fullerene family, Sc2S C2n (n = 40-50) by the introduction of SO2. Chem Commun 46 4818 820... 

Kroto HW (2006) Introduction Space-Pandora s Box. In Rietmeijer FJH (ed) Natural fullerenes and related structures of elemental carbon. Springer, Dordrecht, pp 1-5 Mennella V (2001) Astron Astrophys 367 355-361... 

This chapter will give an overview of the use of NMR spectroscopy in characterization of hydrogenated fullerenes. This first section serves as a general introduction of the importance of NMR as a characterization method in this field. Thereafter, different NMR techniques and methods that have been implemented to derive different chemical and structural properties of hydrogenated fullerenes are reviewed. To conclude this chapter, a more detailed description of the different hydrogenated... 

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