Featured Research

from universities, journals, and other organizations

Evidence to support controversial theory of 'buckyball' formation

Date:
September 15, 2013
Source:
Virginia Tech
Summary:
Researchers report the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle commonly called a buckyball is the result of a breakdown of larger structures rather than being built atom-by-atom from ground up.

Harry Dorn, a professor at the Virginia Tech Carilion Research Institute, poses with models of "buckyballs." His research supports the theory that a soccer ball-shaped nanoparticle commonly called a buckyball is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.
Credit: Virginia Tech

Researchers at the Virginia Tech Carilion Research Institute have reported the first experimental evidence that supports the theory that a soccer ball-shaped nanoparticle commonly called a buckyball is the result of a breakdown of larger structures rather than being built atom-by-atom from the ground up.

Related Articles


Technically known as fullerenes, these spherical carbon molecules have shown great promise for uses in medicine, solar energy, and optoelectronics. But finding applications for these peculiar structures has been difficult because no one knows exactly how they are formed.

Two theories compete regarding the molecular mechanisms that make fullerenes. The first and oldest is the "bottom-up" theory, which says these carbon cages are built atom-by-atom, like the construction of a Lego model. The second, more recent, theory takes a "top-down" approach, suggesting that fullerenes form when much larger structures break into constituent parts.

After several years of debate with little more than computational models in support of how the top-down theory might work, researchers led by Harry Dorn, a professor at the research institute, have discovered the missing link: asymmetrical fullerenes that are formed from larger structures appear to settle into stable fullerenes.

The discovery appeared online Sept. 15 in the journal Nature Chemistry.

"Understanding the molecular mechanics of how fullerenes and their many variations are formed is not just a curiosity," said Dorn, who has been researching metallofullerenes -- fullerenes with a few atoms of metal held within -- for more than two decades. "It would give us insights into new, better ways to prepare them. Fullerenes and metallofullerenes are already involved in hundreds of biomedical studies. The ability to create large numbers of a wide variety of metallofullerenes would be a giant building block that would take the field to new heights."

The medicinal promise of metallofullerenes stems from the atoms of metal caged within them. Because the metal atoms are trapped in a cage of carbon, they do not react with the outside world, making their side-effect risks low in both number and intensity.

For example, one particular metallofullerene with gadolinium at its core has been shown to be up to 40 times better as a contrast agent in magnetic resonance imaging scans for diagnostic imaging than options now commercially available. Current experiments are also directed at using metallofullerenes to carry therapeutic radioactive ions to target cancer tissue.

"A better understanding of the formation of fullerenes and metallofullerenes may allow the development of new contrast agents for magnetic resonance imaging at commercial-level quantities," said Jianyuan Zhang, a graduate student in Dorn's laboratory and the first author of the paper. "These larger quantities will facilitate a next generation of contrast agents with multiple targets."

Dorn's new study hinges on the isolation and purification of approximately 100 micrograms -- roughly the size of several specks of pepper -- of a particular metallofullerene consisting of 84 carbon atoms with two additional carbon atoms and two yttrium atoms trapped inside.

When Dorn and his colleagues determined the metallofullerene's exact structure using nuclear magnetic resonance imaging and single crystal X-ray analysis, they made a startling discovery -- the asymmetrical molecule could theoretically collapse to form nearly every known fullerene and metallofullerene.

All the process would require would be a few minor perturbations -- the breaking of only a few molecular bonds -- and the cage would become highly symmetrical and stable.

This insight, Dorn said, supports the theory that fullerenes are formed from graphene -- a single sheet of carbon just one atom thick -- when key molecular bonds begin to break down. And although the study focuses on fullerenes with yttrium trapped inside, it also shows that the carbon distribution looks similar for empty cages, suggesting regular fullerenes form the same way.

"Not only are the findings presented in Dr. Dorn's paper extremely interesting, but the study represents a real milestone in the field," said Takeshi Akasaka, a professor of chemistry at the University of Tsukuba in Japan and an authority in the field of metallofullerene research, who was not involved in the study. "The study presents physical evidence for a process of metallofullerene creation that most scientists in the field initially scoffed at."

Dorn said scientists have questioned the bottom-up theory of fullerene formation ever since it was discovered that fullerenes were formed from asteroids colliding with Earth and fullerenes were found in interstellar space.

"With this study, we hope to be that much closer to understanding their formation and creating entirely new classes of fullerenes and metallofullerenes that could be useful in medicine as well as in other fields that haven't even occurred to us yet," Dorn said.

"Dr. Dorn's insight into the fundamental process whereby fullerenes are formed is a major contribution to the field," said Michael Friedlander, executive director of the Virginia Tech Carilion Research Institute. "Understanding the molecular steps in their formation is key to realizing fully the potential of this versatile and potentially potent family of chemicals in medicine. Dr. Dorn's contributions to understanding these molecules are paving the way for the formulation of targeted novel diagnostics, therapeutics, and the combination of both -- theranostics. This approach will provide an important component for tomorrow's arsenal of precision medicine."

Dorn and Zhang's research collaborators include Faye Bowles, a graduate student researcher; Marilyn Olmstead, a professor of chemistry; and Alan Balch, a distinguished professor of chemistry; all from the University of California, Davis.


Story Source:

The above story is based on materials provided by Virginia Tech. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jianyuan Zhang, Faye L. Bowles, Daniel W. Bearden, W. Keith Ray, Tim Fuhrer, Youqing Ye, Caitlyn Dixon, Kim Harich, Richard F. Helm, Marilyn M. Olmstead, Alan L. Balch, Harry C. Dorn. A missing link in the transformation from asymmetric to symmetric metallofullerene cages implies a top-down fullerene formation mechanism. Nature Chemistry, 2013; DOI: 10.1038/nchem.1748

Cite This Page:

Virginia Tech. "Evidence to support controversial theory of 'buckyball' formation." ScienceDaily. ScienceDaily, 15 September 2013. <www.sciencedaily.com/releases/2013/09/130915134351.htm>.
Virginia Tech. (2013, September 15). Evidence to support controversial theory of 'buckyball' formation. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2013/09/130915134351.htm
Virginia Tech. "Evidence to support controversial theory of 'buckyball' formation." ScienceDaily. www.sciencedaily.com/releases/2013/09/130915134351.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Who Will Failed Nuclear Talks Hurt Most?

Who Will Failed Nuclear Talks Hurt Most?

Reuters - Business Video Online (Nov. 25, 2014) With no immediate prospect of sanctions relief for Iran, and no solid progress in negotiations with the West over the country's nuclear programme, Ciara Lee asks why talks have still not produced results and what a resolution would mean for both parties. Video provided by Reuters
Powered by NewsLook.com
Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Flying Enthusiast Converts Real-Life Aircraft Cockpit Into Simulator

Reuters - Innovations Video Online (Nov. 25, 2014) A virtual flying enthusiast converts parts of a written-off Airbus aircraft into a working flight simulator in his northern Slovenian home. Jim Drury reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins