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Fullerene – фуллерен, бакибол (молекула углерода C2n в форме полого выпуклого многогранника)

Consist of – состоять из

Entirely – полностью

Resemble – напоминать

Allotrope-аллотропная модификация

Similar – похожий

Link – соединять

Derivative – преобразование

Carbon – углерод

Trap – схватывать

Planar – плоский

Superconductors – супер проводники

Appropriate – подходящий

Discovery – открытие

Prediction – предсказывание

Beam – луг

Discrete – отдаленный

Obtain – получать

Occurrence – появление

Soot – копоть; сажа

Residue – остаток

Lightning discharge – разряд молнии

Interstellar dust – космическая пыль

Current- ток

Purification- чистота; очистка

Layer- слой

Reduce- уменьшать

Property – свойство

Resistance – сопротивление

Develop – развивать

Science fiction – фантастика

Armor – доспех

Describe – описывать

Text 5.

Fullerenes

Fullerenes are a family of carbon allotropes (other allotropes of carbon are graphite and diamond) consisting of molecules composed entirely of carbon atoms arranged in the form of hollow spheres, ellipsoids, or tubes. Each molecule generally has both pentagonal and hexagonal faces.

The most common fullerene is Buckminsterfullerene, in which each molecule is composed of 60 carbon atoms that together take the shape of a soccer ball. It was named after Richard Buckminster Fuller, because its shape resembles Fuller's design of a geodesic dome. By extension, sph erical fullerenes are often called buckyballs, and cylindrical ones are called buckytubes, or, more accurately, carbon nanotubes. Fullerenes are similar in structure to graphite, which is composed of stacked sheets of linked hexagonal rings. In the case of a fullerene, however, the presence of pentagonal (or sometimes heptagonal) rings prevents its sheets from being planar.

Chemists can now produce various derivatives of fullerenes. For example, hydrogen atoms, halogen atoms, or organic functional groups can be attached to fullerene molecules. Also, metal ions, noble gas atoms, or small molecules can be trapped in the cage-like structures of fullerene molecules, producing complexes that are known as endohedral fullerenes. If one or more carbon atoms in a fullerene molecule is replaced by metal atoms, the resultant compound is called a fulleride. Some doped fullerenes (doped with potassium or rubidium atoms, for example) are superconductors at relatively high temperatures

Coining the name

Buckminsterfullerene (C₆₀) was named after Richard Buckminster Fuller, a noted architectural modeler who popularized the geodesic dome. Since buckminsterfullerenes have a similar shape to that sort of dome, the name was thought to be appropriate. As the discovery of the fullerene family came after buckminsterfullerene, the shortened name "fullerene" was used to refer to the family of fullerenes.

Prediction and discovery

In 1970, Eiji Osawa of Toyohashi University of Technology predicted the existence of C₆₀ molecules. He noticed that the structure of a corannulene molecule was a subset of a soccer-ball shape, and he made the hypothesis that a full ball shape could also exist. His idea was reported in Japanese magazines, but did not reach Europe or America.

In molecular beam experiments, discrete peaks were observed corresponding to molecules with the exact masses of 60, 70, or more of carbon atoms. In 1985, Harold Kroto (then at the University of Sussex), James R. Heath, Sean O'Brien, Robert Curl, and Richard Smalley, of Rice University, discovered C₆₀, and shortly thereafter discovered other fullerenes. The first nanotubes were obtained in 1991.

Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of compounds.

Natural occurrence and artificial production

Minute quantities of the fullerenes – in the form of C₆₀, C₇₀, C₇₆, and C₈₄ molecules – have been found in soot and in the residue of carbon arc lamps. These molecules are also produced by lightning discharges in the atmosphere. Some analyses indicate that they are present in meteorites and interstellar dust. Recently, Buckminsterfullerenes were found in a family of minerals known as Shungites in Karelia, Russia.

A common method used to produce fullerenes is to send a large current between two nearby graphite electrodes in an inert atmosphere. The resultant carbon plasma arc between the electrodes cools into sooty residue from which many fullerenes can be isolated.

By 1991, it became relatively easy to produce gram-sized samples of fullerene powder using the techniques of Donald Huffman and Wolfgang Krätschmer. However, purification of fullerenes remains a challenge.

Structural variations

Since the discovery of fullerenes in 1985, a number of structural variations of fullerenes have been found. Examples include:

• buckyball clusters: The smallest member is C ₂₀ (unsaturated version of dodecahedrane) and the most common is C ₆₀

• Nanotubes: Hollow tubes of very small dimensions, having single or multiple walls; potential applications in electronics industry

• Megatubes: Larger in diameter than nanotubes and prepared with walls of different thickness; potentially used for the transport of a variety of molecules of different sizes

• Polymers: Chain, two-dimensional and three-dimensional polymers are formed under high pressure high temperature conditions

• Nano onions: Spherical particles based on multiple carbon layers surrounding a buckyball core; proposed for lubricant

• Fullerene rings

Buckyballs Buckminsterfullerene C₆₀

A soccer ball is a model of the Buckminsterfullerene C₆₀

Carbon nanotubes

Nanotubes are cylindrical fullerenes. These tubes of carbon are usually only a few nanometers wide, but they can range from less than a micrometer to several millimeters in length. They often have closed ends, but can be open-ended as well. There are also cases in which the tube reduces in diameter before closing off. Their unique molecular structure results in extraordinary macroscopic properties, including high tensile strength, high electrical conductivity, high ductility, high resistance to heat, and relative chemical inactivity (as it is cylindrical and "planar" – that is, it has no "exposed" atoms that can be easily displaced). One proposed use of carbon nanotubes is in paper batteries, developed in 2007 by researchers at Rensselaer Polytechnic Institute. Another proposed use in the field of space technologies and science fiction is to produce high-tensile carbon cables required by a space elevator.

Properties

In the past decade, the chemical and physical properties of fullerenes have been a hot topic in the field of research and development, and are likely to continue to be for a long time. Popular Science has published articles about the possible uses of fullerenes in armor. In April 2003, fullerenes were under study for potential medicinal use: Binding specific antibiotics to the structure to target resistant bacteria and even target certain cancer cells such as melanoma. The October 2005 issue of Chemistry and Biology contained an article describing the use of fullerenes as light-activated antimicrobial agents

Task № 1

Answer the questios.

1) Which faces does each molecule have according to the text?

2) What is the short name for buckminsterfullerene?

3) When were first nanotubes obtained?

4) Where have minute quantities of the fulleneres been found?

5) What is a common method used to produce fullerenes?

Task № 2

Put questions to the underlined words

1) The most common fullerene is Buckminsterfullerene.

2) Fullerenes are similar in structure to graphite.

3) Some doped fullerenes are superconductors at relatively high temperature.

4) Kroto, Curl, and Smalley were awarded the 1996 Nobel Prize in Chemistry for their roles in the discovery of this class of compounds.

5) Their unique molecular structure results in extraordinary macroscopic properties.

Task № 3

Match the following words with the correct definition according to the text

1) Nanotubes

2) Buckminsterfullerene

3) Fullerene

4) Buckyballs

5) Megatubes

6) Buckyball clusters

7) Nanotubes

8) Polymers

9) Nano onions

a) are a family of carbon allotropes (other allotropes of carbon are graphite and diamond) consisting of molecules composed entirely of carbon atoms arranged in the form of hollow spheres, ellipsoids, or tubes.

b) Cylindrical fullerenes

c) Are cylindrical cylindrical

d) Chain, two-dimensional and three-dimensional polymers are formed under high pressure high temperature conditions

e) Spherical particles based on multiple carbon layers surrounding a buckyball core; proposed for lubricant

f) The smallest member is C ₂₀ (unsaturated version of dodecahedrane) and the most common is C ₆₀

g) Larger in diameter than nanotubes and prepared with walls of different thickness; potentially used for the transport of a variety of molecules of different sizes

h) Hollow tubes of very small dimensions, having single or multiple walls; potential applications in electronics industry

i) The most common fullerene in which each molecule is composed of 60 carbon atoms that together take the shape of a soccer ball

j) Are spherical fullerene

Task № 4

Find the equivalents to the following words in the text and make up sentences with them Completely, identical, prophesy, remind (of), connect, distant, receive, characteristic, decrease

Task № 5

Give explanations for the following words: molecule, artificial production, atmosphere, Nobel prize, atom, science fiction, antibiotics, bacteria.

Task № 6

Put definite or indefinite articles

_ most common fullerene is Buckminsterfullerene, in which each molecule is composed of 60 carbon atoms that together take _ shape of _ soccer ball. It was named after Richard Buckminster Fuller, because its shape resembles Fuller's design of _ geodesic dome. By extension, spherical fullerenes are often called buckyballs, and cylindrical ones are called buckytubes, or, more accurately, carbon nanotubes. Fullerenes are similar in structure to graphite, which is composed of stacked sheets of linked hexagonal rings. In _ case of _ fullerene, however, _ presence of pentagonal (or sometimes heptagonal) rings prevents its sheets from being planar.

Task № 7

Put the words in brackets into the correct form

Chemists can now (produce) various derivatives of fullerenes. For example, hydrogen atoms, halogen atoms, or organic functional groups can (attach) to fullerene molecules. Also, metal ions, noble gas atoms, or small molecules can (trap) in the cage-like structures of fullerene molecules, (produce) complexes that (know) as endohedral fullerenes. If one or more carbon atoms in a fullerene molecule (replace) by metal atoms, the resultant compound (call) a fulleride. Some doped fullerenes (doped with potassium or rubidium atoms, for example) (be) superconductors at relatively high temperatures.