[FoRK] The Age of Alchemy
Stephen D. Williams
sdw at lig.net
Thu Jan 7 14:24:24 PST 2010
Inert Aluminum? Where's my transparent aluminum??
> Return of the alchemists
> Robert Matthews
> * Last Updated: January 03. 2010 7:58PM UAE / January 3. 2010 3:58PM GMT
> The practical aspect of alchemy generated the basics of modern
> chemistry. Photolibrary
> With its associations with wizards, spells and magic, alchemy is not a
> term you expect to come across in a prestigious research journal. Like
> astrology and divination, the idea of transforming ho-hum materials
> into wondrous ones at the wave of a wand has long been dismissed by
> scientists. Yet last week, the US National Academy of Sciences
> published a paper that not only begins with that taboo word, but even
> claims to explain how to bring about such transformations.
> The implications are certainly startling. According to the authors of
> the paper, it is possible to mimic certain properties of precious
> metals as platinum and palladium using combinations of far more
> mundane materials. And that opens up the prospect of replacing
> expensive strategic metals in many industrial applications by much
> cheaper alternatives.
> The origins of the breakthrough lie in a curious discovery made by
> chemists around 40 years ago. A number of research teams in Europe and
> America reported that when carbon atoms were added to atoms of
> tungsten, the resulting material – tungsten carbide – seemed to
> possess some of the properties of the far more costly metal platinum.
> In particular, it mimicked the ability of platinum to act as a
> catalyst, boosting the efficiency of chemical reactions. Somehow the
> combination of atoms of two different elements were behaving like a
> single “superatom” of an entirely different atom.
> During the 1980s, more examples of the superatom phenomenon emerged.
> Researchers at the California Institute of Technology discovered that
> combinations of aluminium atoms had some of the properties of the far
> rarer metal ruthenium, used as a catalyst by the chemical industry.
> In the search for explanations, attention focused on the key players
> in chemical reactions: electrons. The properties of every atom are
> dictated by the arrangement of these subatomic particles in so-called
> “shells” surrounding the central nucleus of their host atoms.
> The link between these arrangement and chemical properties is famously
> demonstrated by the Periodic Table, the block-like diagram that graces
> the walls of every chemistry lab. Atoms with similar configurations of
> electrons and thus similar properties, such as alkali metals or inert
> gases, end up close to each other.
> The fact that superatoms mimic the behaviour of individual atoms
> suggests that both have similar electron arrangements. That, in turn,
> suggests that new types of superatom could be predicted by using the
> Periodic Table.
> Now a team of researchers at Pennsylvania State University led by Prof
> Welford Castleman has confirmed this, opening the way to a whole new
> branch of chemistry.
> The team’s discovery stems from its work on a superatom constructed
> from 13 aluminium atoms, which studies revealed had properties similar
> to a single atom of iodine. On the Periodic Table, iodine sits in the
> column of so-called halogen elements, which are just one electron
> short of becoming inert gases. That suggests adding one more electron
> to the iodine-like cluster of 13 aluminium atoms would make them
> chemically inert – which is just what the team found.
> Emboldened by this, the team has now used the Periodic Table to
> predict that a superatom made from atoms of titanium and oxygen should
> behave like a single atom of nickel. Their reasoning can be understood
> with basic arithmetic: titanium and oxygen have four and six outermost
> electrons respectively, while nickel has 10 such electrons. The same
> idea has led them to predict that zirconium plus oxygen should act
> like palladium, which – like platinum – is a widely-used but pricey
> industrial catalyst.
> In research published last week in the online early edition of
> Proceedings of the National Academy of Sciences, the team has now
> confirmed these predictions – along with the 40-year-old connection
> between tungsten carbide and platinum. But they have gone further,
> using spectroscopic studies to show that the root cause really is the
> similarity in the electron structures of the superatoms and the atoms
> they mimic.
> Now the team is working its way across the big central block of the
> Periodic Table, consisting of so-called transition metals from
> scandium – used in aerospace alloys – to gold. Their aim is to
> discover other superatoms, and to gauge the extent of their
> similarities to standard atoms.
> Not surprisingly in view of the commercial implications of success,
> the Penn State team is not alone in its quest. Researchers at Virginia
> Commonwealth University recently announced that a cluster of eight
> caesium atoms plus a vanadium atom mimic the magnetic strength of
> manganese. The research team has also predicted that superatoms of
> gold and manganese will be magnetic while not conducting electricity –
> a combination making them useful in some biomedical applications.
> Such discoveries suggest we are witnessing the birth of a whole new
> branch of chemistry, and one that could not have arrived at a better
> time – for many critical technologies are crying out for a
> breakthrough in material science.
> An example is nuclear fusion power, in which the energy source of the
> sun and stars is harnessed in giant reactors known as tokamaks. The
> walls of such reactors are blasted by intense radiation in the form of
> fast moving neutrons, and the resulting damage and replacement
> threatens to make nuclear fusion uneconomic. Reactor walls made of
> superatomic metals may be the answer. The economics of many other
> technologies, from superconducting power cabling to fuel cells, might
> also be transformed by the discovery of low-cost superatomic equivalents.
> Before it fell into disrepute, alchemy had many distinguished
> adherents – among them Sir Isaac Newton. Their 21st century
> successors, armed with a book of spells in the form of the Periodic
> Table, may soon be achieving feats of magic that will astound us all.
> Robert Matthews is Visiting Reader in Science at Aston University,
> Birmingham, England
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