Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

‘Rule-breaking’ molecule could lead to non-metal magnets

03.02.2004


Purdue University scientists have uncovered an unusual material that could lead to non-metallic magnets, which might be lighter, cheaper and easier to fabricate than magnets made of metal.


Purdue chemist Paul Wenthold stands with graduate student Tamara Munsch next to a model illustrating the unusual molecule they analyzed. The radical hydrocarbon has unpaired electrons that face in different directions, a characteristic that makes it unique among non-metallic compounds. The electrons, represented by the binders closer to Wenthold and under a diagram of the molecule itself, "stack up" in a way that can be likened to the way binders lie flat on a shelf but do not face the same direction – as they would in an ordinary radical, represented by the stack farther from him. The fundamental discovery could help in the design of new materials such as non-metal magnets. (Purdue News Service photo/David Umberger)



A team of researchers, including Paul G. Wenthold, has analyzed a radical hydrocarbon molecule whose electrons behave differently than they should, according to well-known principles. The compound is not the only molecule that exhibits such odd behavior in its surrounding cloud of electrons, but it is the first to be discovered that does not include a transition metal.

"In that respect, this is a unique exception to the electron-behavior rule, and it might help chemists think more clearly about where other exceptions lie," said Wenthold, an assistant professor of chemistry in Purdue’s School of Science. "Designing materials with novel properties depends on understanding the forces at work inside their molecules, and understanding the structure of this exceptional molecule could lead to new tools for material design."


The research, which Wenthold conducted with Anna I. Krylov of the University of Southern California and members of both their research groups, appears in today’s (2/ 2) issue of Angewandte Chemie International Edition, a major European chemistry journal. The team deduced the structure of the compound using advanced techniques, including mass spectrometry.

Radical molecules, which contain unpaired electrons and are thus more reactive than molecules without them, have gained household notoriety primarily because so-called "free radicals" in the bloodstream can damage healthy cells. While the molecule Wenthold’s team has investigated is not found in the body and has no household name – it is referred to only by its chemical description, 5-dehydro-1,3-quinodimethane – it has a property that would raise the eyebrows of any observant student in a first-year chemistry course. The surprise stems from the uncommon way its three unpaired electrons arrange themselves around the nuclei in the molecule’s atoms – an arrangement that students learn is virtually fundamental.

"It’s called Hund’s Rule," Wenthold explained. "It says that unpaired electrons line up facing the same direction when they arrange themselves around the molecular center. You might think of them as three-ring binders lying flat on shelves: You want to be able to read the labels on all of their spines, so you lay each binder flat with its spine pointing outward."

Paired electrons, he explained, would resemble two binders stacked one atop another; if their spines were both facing the same way, the top face of the upper binder would not form a flat surface, and it would tend to slide off the lower binder. None of a radical’s unpaired electrons is constrained by this need to face the opposite direction, as they all have their own "shelves," or quantum energy levels.

"Nonetheless, one of the three unpaired electrons in our molecule faces the opposite direction," Wenthold said. "Since this is the first time we’ve ever seen this happen in an organic triradical, it opens up a few new possibilities for materials designers."

Krylov said the possibilities might include the building blocks for molecular magnets.

"People are already trying to build magnets from materials other than metals, such as the polymers that form plastic," she said. "Since magnetism is related to the behavior of unpaired electrons, this compound could be used as a building block for such polymers, leading to non-metallic magnets. It could extend a materials scientist’s options."

The National Science Foundation (NSF)’s Tyrone Mitchell said that non-metallic magnets might have significant advantages over metal ones.

"Non-metal magnets would have several conceivable advantages," said Mitchell, who is program director in the NSF’s chemistry division. "If we can find ways to magnetize hydrocarbons, for example, they would weigh less than metallic magnets, making them attractive to the space program and other commercial applications in which weight is always a concern. And since the raw materials would also be cheaper and easier to fabricate than metal substances, such magnets could conceivably save money in the long run."

Wenthold and Krylov cautioned that such possibilities are only speculation for the moment, and for now the major significance of the find is the fundamental knowledge it provides.

"We still have a lot to learn about molecules such as this one," Wenthold said. "We have a long list of steps that will follow this one, such as comparing this molecule’s properties with one that does not have its unpaired electrons facing different directions. But the unique property this substance exhibits will be of interest in its own right, even before we come up with any actual applications for it. It is one thing to discover magnets – designing them is far more difficult and requires an understanding of what makes them magnets in the first place."

This research was sponsored in part by the National Science Foundation.

Writer: , (765) 494-2081, cboutin@purdue.edu
Source: Paul Wenthold, (765) 494-0475, pgw@purdue.edu
Purdue News Service: (765) 494-2096; purduenews@purdue.edu

Chad Boutin | Purdue News
Further information:
http://news.uns.purdue.edu/html4ever/2004/040202.Wenthold.molecule.html

More articles from Materials Sciences:

nachricht Move over, Superman! NIST method sees through concrete to detect early-stage corrosion
27.04.2017 | National Institute of Standards and Technology (NIST)

nachricht Control of molecular motion by metal-plated 3-D printed plastic pieces
27.04.2017 | Ecole Polytechnique Fédérale de Lausanne

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>