Popular Science: The Magic Molecule

British chemist Sir Harry Kroto is the co-discoverer of buckyballs, a form of carbon made up of 60 atoms and shaped like “a hollow soccer ball.” The discovery won Kroto and his team the Noble Prize in chemistry.

Although it’s not too exciting to look at, this is the world’s first production facility for a newly discovered, exotic material, dubbed “buckyball,” that has such extraordinary potential that chemists and physicists around the country are lining up to pay $1,200 a gram for the stuff, roughly one hundred times the price of gold.

“This is the biggest news in chemistry I could have imagined,” exclaims Robert Whetten of the University of California at Los Angeles. The reason? Together with the plain-Jane carbon particles that make up most of the soot is a carbon molecule with a unique structure, totally different from that of the two previously known forms of carbon.

The discovery of a new kind of carbon came as a stunning surprise to most scientists. Carbon is the most intensely studied of all the elements because it is the basis for most ofthe molecules of life—the organic molecules. Look in any chemistry textbook and youll read that for centuries research showed carbon came in just two basic structures: hard, sparkling diamond, whose carbon atoms are arranged in little pyramids; and dull, soft, slippery graphite, which consists of sheets of carbon-atom hexagons.

Those chemistry textbooks are now obsolete. There’s a new basic form of carbon with an almost unbelievable structure: Its 60 carbon atoms form something that looks like a hollow soccer ball. It is the only molecule of a single element to form a spherical cage.

The molecule’s official name is buckminsterfullerene, because it is shaped like the geodesic dome invented by that American original, Buckminster Fuller. Informally, chemists call it buckyball, or C-60. Its atoms are arrayed in a collection of regular pentagons and hexagons—12 pentagons and 20 hexagons to be precise. It’s one of a newly discovered family of similar molecules that has a related geometry, but different multiples of carbon atoms. Scientists have called this whole family the fullerenes; scores of chemists and physicists are working full blast to unravel their properties.

It’s not just the intellectual kick of a major advance that is energizing the scientific community as much as the discovery of high-temperature superconductors did a few years ago. It’s the prospect that buckyball’s properties will make possible a cornucopia of valuable applications.

“To a chemist it’s like Christmas,” exults Richard Smalley of Rice University in Houston, one of the key players in the buckyball game. To explain, he harkens back to the discovery of benzene in 1825. The benzene molecule is a relatively simple six-carbon ring, yet it’s the parent of countless compounds, from aspirin to nasal decongestants to paints, dyes, and plastics—all made by working with that six-carbon ring. Now chemists hope to perform the same magic with this family of new carbon molecules that is at least 10 times bigger than benzene, with, therefore, even greater possibilities.

It is now clear to researchers that the C-60 molecule is exceptionally stable and resistant to radioactivity and chemical corrosion. It also greedily accepts electrons, but is not reluctant to release them. These and other attributes have scientists and engineers already speculating about microscopic ball bearings, new cancer treatments, lightweight batteries, powerful rocket fuels, and the infinite possibilities in plastics and other organic compounds that have carbon atoms as their backbones.

The world’s first buckyball production facility came onlinThe world’s first buckyball production facility came online early in 1991 at the Materials and Electrochemical Research Corp. in Tucson, assigned the patent to produce research-quantity amounts. The process is hardly elaborate. The heart of the operation is a metal chamber the size of an ordinary bucket. The current that runs through the graphite electrodes inside the chamber is provided by a Sears Craftsman arc welder. After the graphite vaporizes (in what looks like diesel exhaust), the soot is dissolved in toluene, and the solution is spun down to get relatively pure fullerenes. Sounds simple, but the extraction process is tricky, Huffman says.

“At the moment, the problem is that they can’t keep up with the demand,” he adds. “They’re making more than a gram a day, but it’s time-consuming.” Down the hall, though, is the equipment for a tenfold scale-up, with bigger plans on the horizon. “If there’s a really big demand,” Huffman adds, “C-60 ultimately could be produced for pennies a gram. I really think that ten or twenty years down the road there will be large factories producing this material.”

Smalley speculates that buckyballs may not only be among the most common molecules in the universe, but among some of the oldest, if they were indeed created in the seething heat of red giant stars 10 to 20 billion years ago. And because they are large enough to collect smaller particles in collisions, perhaps they served as the primordial nuclei around which the first solid objects coalesced: interstellar dust particles, then rocks, asteroids, comets, and the planets themselves.

Read the complete article at Popular Science.

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