New Fullerene Derivative

PCBM was firstly introduced in PSCs in 1995 [9] and since then no other acceptors can outperform it. However, the photovoltaic properties of the Ceo derivatives can be further enhanced by fine-tuning their LUMO energy levels and improving their absorbance in the visible region. 

However, despite this remarkably high efficiency, ICBA has not shown good performance when used with other low-bandgap polymers. An alternative path to modify the LUMO level of fullerenes for OPV applications was using expensive endohedral fullerenes introduced by Drees and coworkers [85]. 

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As mentioned earlier, there is an interaction of fullerene derivatives with cytochrome c (Witte et al., 2007). The importance of these interactions is quite evident, considering that drags, before reaching their target, interact with serum proteins, cross cellular barriers, and come in contact with enzymes of the metabolic path such as cytochrome P450. Therefore, these studies are really important to develop new fullerene derivatives as potential drags. 

In cycloaddition reactions the [6,6] double bonds of Cjq exhibit a dienophilic character. A large variety of cycloadditions have carried out with Cjq and the complete characterization of the products, mainly monoadducts, has greatly increased our knowledge of fullerene chemistry. These chemical transformations also provide a powerful tool for the functionalization of the fullerene sphere. Almost any functional group can be covalently linked to Cjq by the cycloaddition of suitable addends. Some types of cycloadducts exhibit a remarkable stability for example, they can be thermally treated up to 400 °C without decomposition. This is an important requirement for further side-chain chemistry as well as for possible applications of the new fullerene derivatives, which may be of interest due to their biological activity or as new materials. 

The covalent chemistry of fullerenes has developed very rapidly in the past decade in an effort to modify fuUerene properties for a number of applications such as photovoltaic cells, infrared detectors, optical limiting devices, chemical gas sensors, three-dimensional electroactive polymers, and molecular wires [8, 25, 26, 80-82]. Systematic studies of the redox properties of Cgo derivatives have played a crucial role in the characterization of their unique electronic properties, which lie at the center of these potential applications. Furthermore, electrochemical techniques have been used to synthesize and separate new fullerene derivatives and their isomers as well as to prepare fullerene containing thin films and polymers. In this section, to facilitate discussion of their redox properties, Cgo derivatives have been classified in three groups on the basis of the type of attachment of the addend to the fullerene. In group one, the addends are attached via single bonds to the Cgo surface as shown in Fig. 6(a) and are referred to as singly bonded functionalized derivatives. The group includes... 

In this chapter we concentrate exclusively on the most important aspects of the electrochemistry of 50 and the other pristine higher fullerenes, namely, C70, 75, 73, Cg2, and Cg4. A vast number of derivatives of 50 and a few of C70, 75, and C7g have been prepared, and their redox properties have been studied using electrochemical techniques. However, due to space limitations, it is impossible to cover this subject here and to give it the justice that it deserves. Since several comprehensive reviews on fullerenes and their derivatives have appeared recently, the reader is referred to these for details [6]. Nevertheless, it has been recently discovered that controlled potential electrolysis can be used as a synthetic tool for the preparation of new fullerene derivatives, as well as for the separation of otherwise inseparable fullerene isomers. Thus, a short section covering electrosynthesis of fullerene derivatives is included at the end of this chapter. 

The contribution of discoveries made via electrochemical techniques to the understanding of fullerene chemistry continues at a very fast pace. Perhaps some of the unanswered mechanistic questions regarding the redox behavior of fullerenes will be answered soon. Unquestionably, the role of electrochemistry in the field of fullerenes continues to be strong. As new fullerene-derived materials are prepared, this role will become even stronger. 

Many new electron acceptor materials have been tested in the polymer BHJ blend system, including polymer polymer blend, polymerrCd, polymer oxide, i etc. However, currently they are not as effective as the polymer PCBM system. To further improve the performance of the promising polymer PF-co-DTB, we work on new fullerene derivative as electron acceptor materials. It is shown up to a large amount of (80wt.%) PCBM is required for optimal performance arising from a strong enhancement of... 

Cyclic or-dioxo substrates such as acenaphthenequinone (148) and also N-alkylisatins (149) are deoxygenated in the presence of C o and P(NEt2)3 reductant, giving methanofiillerenes bearing ketone or lactam functionality, respectively. Carbene intermediates are implicated, and the electrochemical properties of the new fullerene derivatives are also reported. ... 

Kim KM, Park HJ, Kim JN, Yoo HJ, Yoon UC (2013) Photoaddition reactions of fullerene C60 with alpha-silyl tert-amines leading to new fullerene derivatives. In ref [18], 523... 

Fullerenes, the new molecular allotrope of carbon, were discovered in 1985 by H. W. Kroto, R. F. Curl and R. E. Smalley [1], who were awarded the Nobel Prize in Chemistry in 1996 due to this seminal scientific finding. However, it was not until 1990 that C o became available in multigram amounts with the preparation procedure of Kratschmer and Huffman [2]. Since then, the chemistry of fullerenes [3] has only been limited by the imagination of chemists. Thus, the development of chemical reactions able to modify the chemical stracture of C ) led to new fullerene derivatives [4] with outstanding structural [5], magnetic [6], superconducting [7], electrochemical [8] and photophysical properties [9]. 

The structure-property relations of fullerenes, fullerene-derived solids, and carbon nanotubes are reviewed in the context of advanced technologies for carbon-hased materials. The synthesis, structure and electronic properties of fullerene solids are then considered, and modifications to their structure and properties through doping with various charge transfer agents are reviewed. Brief comments are included on potential applications of this unique family of new materials. 

Compound 318 used as dipolarophile with ylide 315 (Ar = 2,4,6-Me3C6H2) gives spiro compound 319 (Equation 46) <2001HCA3403>. The 1,3-dipolar cycloaddition of 3-oxo-2-pyrazolidinium ylide 315 (Ar = Ph) with buckminsterfullerene Cgo yields new heterocyclic fullerene derivatives <1995TL2457>. 

Recently, the possibility to use C60 as anti-inflammatory compound has been reported (Huang et al., 2008). Fullerene-xanthine hybrids have been studied to determine if nitric oxide (NO) and tumor necrosis factor-alpha (TNF-a) production in lipopolysaccharide (LPS)-activated macrophages can be inhibited by hybrid administration, finding positive results. The presence of xanthine moiety seems to be essential for the inhibition of LPS-induced TNF-a production, while the fullerene portion ameliorates the efficiency in LPS-induced NO production blockage, leading to a new promising class of potent anti-inflammatoiy agents. It is necessary to mention also the opposite results obtained by an amino acid fullerene derivative tested on human epidermal keratinocytes at concentration from 0.4 to 400 pg/mL. 

In this context, it is worthy to note that the already mentioned Baa behaves as a new cell-penetrating unit, because its presence permits the deliveiy into cells of both cationic and anionic peptides, which are not able to cross the membrane by themselves, further increasing the potentiality of fullerene derivatives (Yang et al., 2007a). 

Yet hands-on experience with 1 and other related compounds showed that free malonic acid groups on fullerenes are rather unstable even under physiological conditions and readily decarboxylate into side products, some of which may show toxicity under certain circumstances (Beuerle et al., 2007). To avoid these potential side effects new polar derivatives of 1 like 3, 4 and 5 have been synthesized (Beuerle et al., 2005 Witte et al., 2007). In these trisadducts the polar endgroups are attached via alkyl spacers to the fullerene core and thus no unwanted decarboxylation... 

Sessler JL, Jayawickramarajah J, Gouloumis A et al. (2006) Guanosine and fullerene derived deaggregation of a new phthalocyanine-linked cytidine derivative. Tetrahedron. 62 2123-2131. 

Due to their unique electronic and chemical properties fullerenes have a tremendous potential as building blocks for molecular engineering, new molecular materials and supramolecular chemistry [54, 133], Many examples of fullerene derivatives (Section 14.1), which are promising candidates for nanotechnological or medical applications, have been synthesized already and even more exciting developments are expected. A detailed description of the potential of fullerene derivatives for technological applications would require an extra monograph. Since this book focuses on the chemical properties and the synthetic potential of fullerenes only a few concepts for fullerene based materials will be briefly presented. 

The discovery of fullerenes in 1985 led to the era of nanomaterials.1 The three-dimensional geometry of these molecules as well as their unique properties distinguishes them from conventional molecules encountered in organic chemistry. Due to recent discoveries in this field, the horizons of this area have broadened to encompass various new molecules such as endohedral fullerenes, nanotubes, carbon nanohorns, and carbon nano-onions. This chapter discusses the electrochemical behavior of some of these carbon nanoparticles with special emphasis on endohedral fullerenes. Since a large number of fullerene derivatives have been prepared and their various electrochemical studies in different solvents and electrolytes have been reported, the electrochemistry of these derivatives is beyond the scope of this text.2 3 Among the other carbon nanoparticles, the electrochemistry of derivatives of carbon nanotubes has been reported. These studies have been highlighted in the final part of the chapter. 

This indicates that there is neither a strong through-band electronic interaction nor a through-space interaction between the fullerene moiety and the attached group [75,81,110], An exception to this is the fullerene derivatives 5 (Fig. 6) in which the UV spectrum shows two new bands at 455 and 500 nm that are not observed in the pyrene or in the pure fullerene spectra [75], Moreover, the solvent... 

Investigations concerning the synthesis and electrochemical behavior of a new class of acceptor-substituted isoxazolofullerenes have been reported. In this instance, such fullerene derivatives were synthesized by Suzuki coupling (Eq. (89)) [142]. 

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