Fullerenes and Nanotubes

Department of Electrical Engineering and Computer Science and Department of Physics Massachusetts Institute of Technology, 

Erancis Bitter Magnet Laboratory Massachusetts Institute of Technology, 

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. 

Regarding a historical perspective on carbon nanotubes, very small diameter (less than 10 nm) carbon filaments were observed in the 1970 s through synthesis of vapor grown carbon fibers prepared by the decomposition of benzene at 1100°C in the presence of Fe catalyst particles of 10 nm diameter [11, 12]. However, no detailed systematic studies of such very thin filaments were reported in these early years, and it was not until lijima s observation of carbon nanotubes by high resolution transmission electron microscopy (HRTEM) that the carbon nanotube field was seriously launched. A direct stimulus to the systematic study of carbon filaments of very small diameters came from the discovery of fullerenes by Kroto, Smalley, and coworkers [1], The realization that the terminations of the carbon nanotubes were fullerene-like caps or hemispheres explained why the smallest diameter carbon nanotube observed would be the same as the diameter of the Ceo molecule, though theoretical predictions suggest that nanotubes arc more stable than fullerenes of the same radius [13]. The lijima observation heralded the entry of many scientists into the field of carbon nanotubes, stimulated especially by the un- 

Y2 Cg2 denotes two Y atoms inside a Cg2 fullerene [19], Thus far, only small quantities of endohedrally-doped fullerenes have been prepared and only limited investigations of endohedrally-doped crystalline materials have been reported but steady progress is being made both in synthesis and in properties measurements [20]. 

and Haddon, R. C., Chemistry of single-walled carbon nanotubes, Acc. Chem. Ses., 2002, 35,1105-1113. 

Diederich, F. and Gomez-Lopez, M., Supramolecular fullerene chemistry, Chem. Soc. Rev., 1999, 28, 263-277. 

Fullerenes were discovered in the mid 1980s by two American scientists, Robert Curl and the late Richard Smalley, along with British scientist Harold Kroto. The three went onto share the 1996 Noble Prize in Chemistry for their work in this area. Fullerene research led to the discovery of carbon nanotubes in the early 1990s by Japanese scientist Sumio lijimo. 

Fullerenes can also act as hosts. The reactive surface of the Cgo shell can be utilised to attach a plethora of functional groups. An elegant example uses a fullerene crown ether host as an electrochemical sensor for K+. Compound 5.31 incorporates a dibenzo[18]crown-6 in close proximity to the Cgg surface, acfing as fhe 

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Buckminsterfullerene (Chapter 11 essay Carbon Clusters Fullerenes and Nanotubes ) Name given to the Cgo cluster with structure resembling the geodesic domes of R Buck minster Fuller see front cover... 

Benzene Dreams and Creative Thinking Carbon Clusters Fullerenes and Nanotubes... 

In conclusion, such three-dimensional carbon-based nanostructures as fullerenes and nanotubes constitute scaffolds whose efficient functionalization and derivatization... 

T. Ebbesen. In Fullerenes and Nanotubes, edited by Pierre Delhaes and P. M. Ajayan, Gordon and Breach, Paris, France, 1998. Series World of Carbon, volume 2. 

At the end of the twentieth century, in the area of physics, and later in the area of chemistry extraordinarily important experimental results were produced, which gave rise to a new concept of nano-world. Development of high resolution electron microscopes allows detection of not only nano-dimensional particles but also large molecules. New types of matter such as spheroidal molecules with a hollow core (fullerenes and nanotubes), nanosized phases formed by a few atoms of metals... 

Research in graphite intercalates has paved the way for significant current interest in intercalation compounds of the fullerenes (Box 7.1) and carbon nanotubes, which represent wrapped up versions of graphite sheets. Graphite intercalation compounds have been prepared with intercalated fullerenes and nanotubes. We will return to carbon nanotube chemistry in Chapter 15. 

A further question which may be answered by X-ray is that of planarity. Recent papers206,207 disclose that of the thousands of possible PAHs with 10 rings, the vast majority should be nonplanar, even chiral, structures resulting from steric factors. Highly notable examples of nonplanar PAHs include helicenes, fullerenes, bowl-shaped components of fullerenes, and nanotubes.206,207 Several intriguing species have been prepared in which the rings are forced out of planarity due to intramolecular steric interaction between substituents. These interactions become important when the angles by which substituents protrude from the sp2 periphery are such that they would approach adjacent substituents closer than allowed by van der Waals radii. 

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