Researchers discover a new class of magic atomic clusters called superhalogens

Feb 11, 2011
Researchers discover a new class of magic atomic clusters called superhalogens
This image illustrates MnxCl2x+1clusters - new class of magnetic superhalogens.The violet and green spheres represent Mn and Cl atoms, respectively. Image courtesy of Puru Jena, Ph.D./VCU, and Anil Kandalam, Ph.D./McNeese State University.

(PhysOrg.com) -- An international team of researchers has discovered a new class of magnetic superhalogens – a class of atomic clusters able to exhibit unusual stability at a specific size and composition, which may be used to advance materials science by allowing scientists to create a new class of salts with magnetic and super-oxidizing properties not previously found.

The discovery, which was published Feb. 10 in the Early View issue of the international chemistry journal Angewandte Chemie International Edition, was based on theoretical work by researchers from Virginia Commonwealth University, McNeese State University, and Peking University in China, and experimental work at Johns Hopkins University.

Unlike conventional superhalogens that are composed of a at the core and surrounded by halogen atoms, the magnetic superhalogens discovered by this team are composed of stoichiometric metal-halogen moieties at the core to which an additional halogen is attached.

The new chemical species known as magnetic superhalogens mimic the chemistry of halogens which are a class of elements from the periodic table, namely, iodine, astatine, bromine, fluorine and chlorine. The word halogen means "salt-former," and when one of the elements above combines with sodium, they can form a salt.

Specifically, the cluster is MnxCl2x+1, where x = 1, 2, 3, and so on, have manganese and chlorine atoms as a core to which only one chlorine atom is attached. The manganese atoms carry a large magnetic moment and therefore make these superhalogens magnetic.

"One can now design and synthesize yet unknown magnetic superhalogens by changing the metal atom from manganese to other transition metal atoms and changing chlorine to other halogen atoms. In addition to their use as oxidizing agents, being magnetic opens the door to the synthesis a new class of salts," said lead investigator Puru Jena, Ph.D., distinguished professor of physics at VCU.

According to Jena, superhalogens are like halogens, in the sense they form negative ions, but their affinity to attract electrons is far greater than those of any halogen atoms. Negative ions are useful as oxidizing agents, for purification of air and in serotonin release for uplifting mood.

"Superhalogens can do the same thing as halogens can do, only better," said Jena. "The ability of superhalogens to carry large quantities of fluorine and chlorine can be used for combating biological agents as well."

"In addition, superhalogens, due to their large electron affinity, can involve inner core electrons of metal atoms in chemical reaction, thus fundamentally giving rise to new chemistry," said Jena.

In October, Jena and his colleagues reported the discovery of a new class of highly electronegative chemical species called hyperhalogens, which use superhalogens as building blocks around a metal atom. The chemical species may have application in many industries.

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Quantum_Conundrum
3.7 / 5 (3) Feb 11, 2011
The manganese atoms carry a large magnetic moment and therefore make these superhalogens magnetic


Interesting.

I wonder of these molecules could be covered in something inert, such as glass, to prevent them from reacting, and therefore make a magnet for use in a nano-engine or nano-generator?
sstritt
3 / 5 (2) Feb 11, 2011
More powerful batteries?
Quantum_Conundrum
3.7 / 5 (3) Feb 11, 2011
More powerful batteries?


Maybe. Depends on how energy dense the material can be. A large molecule obviously takes up more space than a pure element, so it would need to be much better on a molecular level, or have some other properties that make up for this extra size. Else the conventional material will beat it on pure density and cost-effectiveness.

Advanced materials cost time, money, and energy to make. Such material are then in an up-hill battle, since they need to out-perform the conventional material by a large enough margin and for a long enough life-time to make up the cost difference before they have "broken even".

In military applications, space agencies, and R&D, costs usually aren't the limiting factor, so these molecules will most likely find use in these fields first.
bugmenot23
5 / 5 (1) Feb 11, 2011
This is chemistry, why the reference to 'magic atoms'?
sstritt
3 / 5 (2) Feb 11, 2011
This is chemistry, why the reference to 'magic atoms'?

I think they meant magnetic. They don't proofread their headlines. My all time fave was a story about robots programmed to care for tomato plants. The title was "MIT Develops Robot Tending Tomatoes" instead of "Tomato Tending Robots"
Quantum_Conundrum
1 / 5 (1) Feb 11, 2011
This is chemistry, why the reference to 'magic atoms'?

I think they meant magnetic. They don't proofread their headlines. My all time fave was a story about robots programmed to care for tomato plants. The title was "MIT Develops Robot Tending Tomatoes" instead of "Tomato Tending Robots"


With a colon, or the prepositon "for" the original wording would be correct.

"MIT Develops Robot: Tending Tomatoes"

or

"MIT Develops Robot for Tending Tomatoes"

===

Back on topic:

"Magic atoms" may be a reference to the fact that these molecules behave like individual atoms in the sense of their halogenic properties.
sstritt
3 / 5 (2) Feb 11, 2011
"Magic atoms" may be a reference to the fact that these molecules behave like individual atoms in the sense of their halogenic properties.

You're probably right. Must have something to do with magic numbers of the nucleons and the stability of the cluster. Still, very confusing to use the term magic in the title and then never reference it again.
PinkElephant
not rated yet Feb 11, 2011
The title was "MIT Develops Robot Tending Tomatoes" instead of "Tomato Tending Robots"
Actually that's just a case of a phrase that can be read two ways (showing how imprecise English syntax can be.)

The "Tending" in the original title could be read as equivalent to "That Tends".

Of course the other meaning, as you pointed out, would be equivalent to inserting a hyphen between "Robot" and "Tending".