Prof. Lawrence Scott (Chemistry) with a model of the buckminsterfullerene, or "buckyball," molecule. (Photo by Gary Gilbert)
In a significant first, Prof. Lawrence Scott (Chemistry) and colleagues have devised a 12-step route to create C60 buckyballs in the lab from readily available materials. The team reported its findings in the Feb. 22 edition of the journal Science.
Scott's co-authors on the Science article include several graduate and post-doctoral research assistants at Boston College and one former undergraduate [see related story].
Collecting buckyballs has been an inexact science that has required vaporizing a graphite rod with a laser or an electric arc and picking up the pieces. Until now, scientists haven't been able to synthesize buckminsterfullerenes from start to finish in the laboratory.
The new method is expected to make possible the directed laboratory preparation of other, more complex fullerenes that can't be made by vaporizing graphite. The 60-atom buckyball is the best known of the fullerenes, but others of varying sizes, each representing a new elemental form of carbon, may be produced.
The discovery of the C60 buckyball won Harold Kroto of Great Britain and Americans Robert Curl Jr. and Richard Smalley the Nobel Prize in Chemistry in 1996. To chemists, this identification of a new form of carbon with unique properties was akin to "Columbus bumping into America," said Scott. "It opened the door to a new world."
Buckyballs are seen as having many valuable uses. Scott said one potential application is in the manufacture of lightweight superconductors that could provide significant savings in energy.
Studies have indicated as much as 20 percent of the electricity produced in the United States is lost as heat to the environment due to resistance from metal alloys currently used in power lines, according to Scott. Superconductors offer no resistance, so wires made of superconducting materials theoretically could increase the nation's electrical power by as much as one-fifth, he said.
Meantime, biochemists have seen a use for C60 in the treatment of AIDS, particularly in shutting down an enzyme required by HIV, the virus that causes the disease, he said.
Scott says the method pioneered by his team will allow researchers to synthesize new carbon fullerenes of more complex makeup. "We need to know what the properties of these molecules are," Scott said. "They may also have uses in superconductivity or in fighting AIDS, but who knows what else? We'll never know unless we discover them."
The process described by Scott and colleagues involves subjecting a molecule they synthesized to extremely high temperatures through a process called flash-vacuum pyrolysis. No other fullerenes save C60 buckyballs are formed as byproducts.
"We are able to isolate C60 and put it in a bottle. Nobody's ever done that before," said Scott. "An important part of this for the chemist is that we can shoot for C60 and make only C60. We have now shown there are proven methods available to make a pre-selected fullerene."
In a recent interview, Scott used colorful similes to offer a layman's description of his work. He described the traditional method of collecting fullerenes as a haphazard process of vaporizing graphite and then sifting the trace materials to see what is found.
"It's like painting in a black room with the lights turned off. You throw colors around and hope that a painting results. You turn the lights on and hope there will be something on the canvas. Maybe by accident it will come out looking like a tree.
"I'd like to be able to paint the tree, or the graceful tiger, or the mountain - to choose what I want to paint and paint it."
He said the method devised by his team offers a means to make desired molecules by design, opening the way to greater exploration of the unique properties of fullerenes.
"It's like finding a door and opening it," he said. "After passing through, you can go anywhere you want."
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