[rael-science] Atomic bond types discernible in single-molecule images‏

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http://www.bbc.co.uk/news/science-environment-19584301

13 September 2012 Last updated at 21:36 GMT

Atomic bond types discernible in single-molecule images

By Jason PalmerScience and technology reporter, BBC News
Nanographene AFM imageLook closely: the bonds at centre are shorter than those at the edges, as they involve more electrons
A pioneering team from IBM in Zurich has published single-molecule images so detailed that the type of atomic bonds between their atoms can be discerned.
The same team took the first-ever single-molecule image in 2009 and more recently published images of a molecule shaped like the Olympic rings.
The new work opens up the prospect of studying imperfections in the "wonder material" graphene or plotting where electrons go during chemical reactions.
The team, which included French and Spanish collaborators, used a variant of a technique called atomic force microscopy, or AFM.
AFM uses a tiny metal tip passed over a surface, whose even tinier deflections are measured as the tip is scanned to and fro over a sample.
The IBM team's innovation to create the first single molecule picture, of a molecule called pentacene, was to use the tip to pick up a single, small molecule made up of a carbon and an oxygen atom.
This carbon monoxide molecule effectively acts as a record needle, probing with unprecedented accuracy the very surfaces of atoms.
It is difficult to overstate what precision measurements these are.
The experiments must be isolated from any kind of vibration coming from within the laboratory or even its surroundings.
They are carried out at a scale so small that room temperature induces wigglings of the AFM's constituent molecules that would blur the images, so the apparatus is kept at a cool -268C.
While some improvements have been made since that first image of pentacene, lead author of the Science study, Leo Gross, told BBC News that the new work was mostly down to a choice of subject.
Nanographene AFM imageTiny distortions to the regular hexagonal pattern of carbon bonds is what interests the researchers
The new study examined fullerenes - such as the famous football-shaped "buckyball" - and polyaromatic hydrocarbons, which have linked rings of carbon atoms at their cores.
The images show just how long the atomic bonds are, and the bright and dark spots correspond to higher and lower densities of electrons.
Together, this information reveals just what kind of bonds they are - how many electrons pairs of atoms share - and what is going on chemically within the molecules.
"In the case of pentacene, we saw the bonds but we couldn't really differentiate them or see different properties of different bonds," Dr Gross said.
"Now we can really prove that... we can see different physical properties of different bonds, and that's really exciting."
The team will use the method to examine graphene, one-atom-thick sheets of pure carbon that hold much promise in electronics.
But defects in graphene - where the perfect sheets of carbon are buckled or include other atoms - are currently poorly understood.
The team will also explore the use of different molecules for their "record needle", with the hope of yielding even more insight into the molecular world.

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"Ethics" is simply a last-gasp attempt by deist conservatives and
orthodox dogmatics to keep humanity in ignorance and obscurantism,
through the well tried fermentation of fear, the fear of science and
new technologies.
 
There is nothing glorious about what our ancestors call history, 
it is simply a succession of mistakes, intolerances and violations.
 
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WARNING FROM RAEL: For those who don't use their intelligence at its
full capacity, the label "selected by RAEL" on some articles does not
mean that I agree with their content or support it. "Selected by RAEL"
means that I believe it is important for the people of this planet to
know about what people think or do, even when what they think or do is
completely stupid and against our philosophy. When I selected articles
in the past about stupid Christian fundamentalists in America praying
for rain, I am sure no Rael-Science reader was stupid enough to
believe that I was supporting praying to change the weather. So, when
I select articles which are in favor of drugs, anti-semitic,
anti-Jewish, racist, revisionist, or inciting hatred against any group
or religion, or any other stupid article, it does not mean that I
support them. It just means that it is important for all human beings
to know about them. Common sense, which is usually very good among our
readers, is good enough to understand that. When, like in the recent
articles on drug decriminalization, it is necessary to make it
clearer, I add a comment, which in this case was very clear: I support
decriminalizing all drugs, as it is stupid to throw depressed and sad
people (as only depressed and sad people use drugs) in prison and ruin
their life with a criminal record. That does not mean that there is
any change to the Message which says clearly that we must not use any
drug except for medical purposes. The same applies to the freedom of
expression which must be absolute. That does not mean again of course
that I agree with anti-Jews, antisemites, racists of any kind or
anti-Raelians. But by knowing your enemies or the enemies of your
values, you are better equipped to fight them. With love and respect
of course, and with the wonderful sentence of the French philosopher
Voltaire in mind: "I disapprove of what you say, but I will defend to
the death your right to say it".