Sciencemadness Discussion Board

Superatoms

halogen - 10-1-2006 at 20:22

I remember reading a brief bit about superatoms particularly clusters of aluminium that act as one atom chemically. Does anyone know anything more about this. It seems they are mostly oxygen resistant and act like "superhalogens" whatever that means. Most important, how are they made?

DeAdFX - 10-1-2006 at 21:37

I was kind of intrested in these super atoms but I gave up fairly fast. The only thing I could find were PR statements which provided nothing "usefuL".

I think one of the pr statements provided a vague synthesis. Like needing aluminum(no shit) and some other stuff.. Kinda anaglous(sp) to the hey GUYS!! I know a high explosive that involves acetone, H2O2 and HCl kinda shit the kewl sites spew outta there ass.

[Edited on 11-1-2006 by DeAdFX]

DrP - 11-1-2006 at 07:37

This site - (http://www.discover.com/issues/apr-05/rd/super-atoms/) - seems to suggest that they have been made by 'laser vapourisation' - but it doesn't say much.

QUOTE:
To create the clusters, Castleman and his colleagues used a process called laser vaporization. A high-energy laser coaxed “seeds” from an aluminum rod into merging by trapping them in a pressurized stream of helium gas.


- some other sites I looked at mentioned Si and C clustering.

Bit off topic maybe but - my friend used silver 'island' clusters on a glass slide to act as amplifiers for Raman spectroscopy. I think that the theory behind this was that if the wavelength of the surface phonons were the same/similar to the size of the cluster, then the electronic structure in the cluster resonated under the incident radiation to amplify the Raman scattering. He was actually looking at the raman spec of nicotine amounst other things - a ran a mile when he got out a bottle of pure nicotine - he had no fume cupboard and decided he'd hold his breath whilst preparing the sample in a small room with no ventilation!

Morgan - 25-3-2011 at 08:28

An Alchemist's Dream: Superatoms Mimic Elements
http://www.physorg.com/news199634925.html

Morgan - 25-3-2011 at 17:51

Just a few crumbs/tidbits.

"Schmidt-Ott hopes to find atom clusters with new unique magnetic, optical or electrical properties, which would also be stable enough to create crystals or other solid forms. Potential applications include catalysts in fuel and extra-conductive crystals."
http://www.physorg.com/news134129791.html

Reader comments.
"delocalization. what makes this more than just "metal molecules" is the fact that the nuclei are loosely associating with one another, held by a delocalized electron cloud, resulting in properties similar to that of an atom with the equivalent effective nuclear mass as that of the sum of the cluster. like it says, if crystallization can occur, you've got the potential for cheap heavy catalysts."

"It sounds to me more like a molecule of Ag9 and Ag13 etc.
IMHO the word "super atom" implies fusion at the nuclear level. Aren't these just molecules of Silver that have different properties than silver in its natural state? I recall sulphur has very different properties depending on its molecular form."

Mixell - 26-3-2011 at 04:02

Morgan, not exactly, the difference between molecules and super atoms is that molecules are bonded via the electrons, but super atoms posses also some sort of nucleus bonding, you can say its some kind of a molecule, but in reality those clusters behave more like atoms than molecules.

blogfast25 - 26-3-2011 at 06:23

In other words it's a quantum system, made up of several atoms 'sharing' an electron cloud. Sounds much like a molecule to me, albeit an exotic one...

I hope it doesn't all end up like the infamous 'polywater'!

Wizzard - 26-3-2011 at 07:14

Isnt this also what a Bose-Einstien condensate does?

woelen - 26-3-2011 at 11:47

No, a bose-einstein condensate is supercooled matter (just a little above 0 K) such that the wave functions of the atoms spread out in space and many of these wave functions combine to make a single big wave function, which gives the material of a kind of strange fluid. These bose-einstein condensates are not molecules. They only can exist at very low temperatures, where the energy of the atoms becomes very low and hence their wave-like behavior exhibits unusual large wave lengths.

The 'super atoms' mentioned here are molecules, just as blogfast25 says. They, however, have exotic modes of bonding.

Morgan - 26-3-2011 at 18:49

"It is fascinating to imagine that new periodic tables of superatoms might be drawn and that this may lead to a new chemistry of superatoms ..."
Platinum nanoclusters go magnetic
http://nanotechweb.org/cws/article/tech/26782

Morgan - 26-3-2011 at 19:06

"These findings support the contention that there should be no limitation in finding clusters, which mimic virtually all members of the periodic table."
Multiple valence superatoms
http://www.pnas.org/content/103/49/18405.abstract?maxtoshow=...

Morgan - 27-3-2011 at 07:07

Quote: Originally posted by Mixell  
Morgan, not exactly, the difference between molecules and super atoms is that molecules are bonded via the electrons, but super atoms posses also some sort of nucleus bonding, you can say its some kind of a molecule, but in reality those clusters behave more like atoms than molecules.


I mentioned both sides in the reader comments just to present opposing viewpoints. Allotropes seem akin to superatoms even if they aren't considered so.
"Allotropes are different structural forms of the same element and can exhibit quite different physical properties and chemical behaviours. The change between allotropic forms is triggered by the same forces that affect other structures, i.e. pressure, light, and temperature. Therefore the stability of the particular allotropes depends on particular conditions."
http://en.wikipedia.org/wiki/Allotropy
http://en.wikipedia.org/wiki/Superatom

blogfast25 - 27-3-2011 at 10:18

"It is fascinating to imagine that new periodic tables of superatoms might be drawn and that this may lead to a new chemistry of superatoms, offering a fantastic perspective for the future of young chemists," he added.

Hmmm… I hope they'll still concentrate on getting the simpler little critters to do what they’re supposed to do…
:)