Buckminsterfullerene, structure

Confirming its structure required isolating enough Cgo to apply modern techniques of structure determination. A quantum leap in fullerene research came in 1990 when a team led by Wolfgang Kratschmer of the Max Planck Institute for Nuclear Physics in Heidelberg and Donald Huffman of the University of Arizona successfully prepared buckmin-sterfullerene in amounts sufficient for its isolation, purification, and detailed study. Not only was the buckminsterfullerene structure shown to be correct. 

Incidentally, balls made of strips of silk are popular decorations for display in Japan. They are called temari, and Figure 1-8 shows one with the pattern of the buckminsterfullerene structure [1-19]. 

Figure 128. The dual of the hexagonal faces of the buckminsterfullerene structure and the count of Kekule structures obtained by rotation of the CC double and CC single bonds within a single benzene ring of the Fries structure of Ceo shown in Figure 127.

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... 

Fullerenes are described in detail in Chapter 2 and therefore only a brief outline of their structure is presented here to provide a comparison with the other forms of carbon. The C o molecule, Buckminsterfullerene, was discovered in the mass spectrum of laser-ablated graphite in 1985 [37] and crystals of C o were fust isolated from soot formed from graphite arc electrodes in 1990 [38]. Although these events are relatively recent, the C o molecule has become one of the most widely-recognised molecular structures in science and in 1996 the codiscoverers Curl, Kroto and Smalley were awarded the Nobel prize for chemistry. Part of the appeal of this molecule lies in its beautiful icosahedral symmetry - a truncated icosahedron, or a molecular soccer ball, Fig. 4A. 

Buckminsterfullerene (Cm or Buckyball ) is structurally related to corannulene. In which molecule would you expect 7U-orbital overlap be more effective Explain. How many chemically unique carbons are there in C6o Measure CC bond distances. How many unique distances are there Is each benzene fully delocalized or is one resonance contributor more important than the other ... 

Since the discovery of buckminsterfullerene (C o) [85NAT(318)162] and other fullerenes (Cig. C70), these molecules have been intensely studied, both experimentally and theoretically. Likewise, several reports on heterofullerenes containing heteroatoms such as nitrogen and boron have appeared (91JPC4948 91JPC10564). The incorporation of heteroatoms is expected to modify the structural and electronic features of these structures, and have thus attracted some interest. 

Chemists were greatly surprised when soccer-ball-shaped carbon molecules were first identified in 1985, particularly because they might be even more abundant than graphite and diamond The C60 molecule (10) is named buckminsterfullerene after the American architect R. Buckminster Fuller, whose geodesic domes it resembles. Within 2 years, scientists had succeeded in making crystals of buckminsterfullerene the solid samples are called fullerite (Fig. 14.32). The discovery of this molecule and others with similar structures, such as C70, opened up the prospect of a whole new field of chemistry. For instance, the interior of a C60 molecule is big enough to hold an atom of another element, and chemists are now busily preparing a whole new periodic table of these shrink-wrapped atoms. 

Scientists identified the first carbon nanotubes in 1991. They sealed two graphite rods inside a container of helium gas and sent an electric discharge from one rod to the other. Much of one rod evaporated, but out of the inferno some amazing structures emerged (see illustrations). As well as the tiny 60-atom carbon spheres known as buckminsterfullerene—which had been known since 1985—long, hollow, perfectly straight carbon nanotubes were detected. 

The existence of a stable Cgg molecule, Buckminsterfullerene(BF) was recently proposed(14). In the suggested structure, twelve regular pentagons and twenty hexagons are connected to form an almost perfectly spherical pattern of icosahedrai symmetry as in Figure 10. 

C14-0135. S ° of graphite is 3 times larger than S ° of diamond. Explain why this is so. (You may need to review the structures and properties of graphite and diamond in Section 11-.) Buckminsterfullerene is a solid that consists of individual molecules with formula Cgo. Is the molar entropy of buckminsterfullerene larger or smaller than that of graphite How about the entropy per gram Explain. 

There now are known to be a whole family of caged carbon structures having various numbers of carbon atoms, including C30, C50, C7o, C72, C76, Cg4, and the huge C540. The name fullerene has replaced the unwieldy, Buckminsterfullerene used to describe this general spheroid structure of carbon, although they still are referred to as Buckyballs . 

FIGURE 13.13 The structure of buckminsterfullerene, C60.The structure consists of five- and six-membered rings. 

It is outside the scope of this Chapter to undertake a comprehensive review of structure-property relationships for the different forms of carbon. However, a limited comparison of properties is useful for illustrating the influence of chemical bonding upon the properties of diamond, graphite and Buckminsterfullerene, Qo, Table 4. Carbynes are omitted from the comparison since insufficient is known of their properties. 

Bubbly liquid, structure of, 12 7 Buccal drug dehvery, 9 48 Bucherer reaction, 9 279 Bucherer synthesis, 2 571 Buchner, Edward, 11 8 Buckingham s theorem, 3 589 Buckingham Pi theorem, 11 744 Buckminsterfullerene (Ceo), 22 719 photovoltaic effects in, 22 220 Buckminsterfullerenes, 4 735 12 228. 

Fullerenes (originally buckminsterfullerenes) are a new class of carbon-only molecules the first example discovered in 1985 (Kroto et al., 1985), being composed of 60 carbon atoms arranged in a soccer ball structure (C60). The condensed aromatic... 

Fullerenes are cage-like carbon structures which derive from a graphene sheet where a few six-membered rings are replaced by five-membered ones which forces the layer into a bent shape. Placing the pentagons at suitable positions, a spherical structure of 60 carbon atoms is obtained - the buckminsterfullerene. Fullerenes with... 

Figure 4.19C shows Ceo, which is one type of fullerene discovered in 1985. It was given the name buckminsterfullerene because it resembles the geodesic-domed structure designed by architect R. Buckminster Fuller. Also known as buckyballs, Ceo is just one of several fullerenes that have been discovered. Others have been shown to have the formula C70, C74, and C82. Because of their spherical shape, researchers have speculated that fullerenes might make good lubricants. 

The 1996 Nobel Prize in chemistry was awarded to three American scientists for their identification of a new allotrope of aromatic carbon molecules called fullerenes. These unusual carbon molecules form a closed-cage structure of joined carbon atoms. The original soccer ball-shaped carbon molecule called buckminsterfullerene contained 60 carbon atoms and was nicknamed Bucky Ball in honor of Buckminster Fuller (1859—1983), who used similar shapes in some of his architectural structures. Since then additional organic pentagon structures beyond the original icosahedral fullerene (C ) have been developed, all with an even... 

The preceding section indicated the importance of corannulene as the smallest member of the family of bowl-shaped, polynuclear aromatic hydrocarbons modeling the surface of buckminsterfullerene. Surprisingly, despite its obvious significance in relationship to the theory of aromaticity, 8 had not attracted the attention of chemists prior to the first report of its synthesis in 1966." As Barth and Lawton noted ... to the time of our first report, it appears this structure had neither adoriied the jacket or end cover of any book nor served as a symbol of an international symposium. More than that, corannulene does not appear to have been suggested in the chemical literature prior to 1966. 

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