Detailed Images Show Intra-Molecular Bonds

Techmeology writes "A team from IBM in Zurich has published images of molecules that are detailed enough to show the lengths of atomic bonds. '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.' This allows an analysis of imperfections in the molecular structure (abstract). The team plans to use the method to examine molecules of graphene."

Comments

wrong paper

[Anonymous Coward]

the writeup describes an earlier paper, not the recent one that was in Science. they previously showed that you can look at planar molecules like pentacene with afm, here they showed that you can see minor differences in the bond lengths to distinguish single/double bonds.

Re:wrong paper

[FrangoAssado]

Pauling is really great, I agree that he should be more well-known (I, myself, am partial to Dirac, who predicted the existence of anti-matter out of pure math). But you have to realize that Newton and (maybe to a lesser degree) Einstein contributions were of another class.

Newton took Galileo's ideas -- that things tend to keep moving if they're left alone -- and built a whole mathematical theory on top of that, inventing calculus in the process. In a sense, it was the beginning of what we today call Physics.

Einstein was the first to notice (and convinced everyone) that the Lorentz transformation is not just a mathematical trick, it's the very way the space and time works. This itself was not that impressive, he was just giving a "new spin" on what everyone had already observed. But then he went on to show that the "right way" to understand gravity is by noting that it's just a side-effect of mass bending the space and time -- this has lots of consequences that were unknown at the time, like gravity bending light, gravity making time pass at different rates, and a lot other stuff, all of which turned out to be right.

Quantum Mechanics and its implications (like the electron shell), on the other hand, were discovered bit by bit by a lot of different people. That's why no one is hugely famous for it (even though there are certainly big names like Planck, Einstein, Bohr, Heisenberg, Born, Schrodinger, Dirac, Pauli, etc.).

Bonds

[jfdavis668]

James Bonds

Nice

[Animats]

Nice. AFMs have been imaging atoms for about two decades (and yes, they do look like spheres). Being able to see intermolecular bonds is a big step forward.

AFMs are amusing. The idea is so simple - mechanically scan atoms with a really sharp point. Everyone had assumed that you'd have to scan atoms with electron beams (as with electron microscopes) or X-rays (as with X-ray diffraction), using some particle much smaller than the atoms being scanned. Then Quate and Gerber figured out how to scan atoms mechanically. Which sounds like a really silly idea, but works.

An AFM works like a mechanical record player. It's a pointy needle on a positioner made using piezoelectric elements. Raster scan signals are applied to the positioners to get a classic TV-type scan, and the third axis has its position measured and is servoed until the point touches the sample. Height measurements come out. Basic AFMs aren't very complicated or very big.

It took a surprisingly long time to come up with this idea. It was invented in 1986. One probably could have been built in 1946, and certainly in 1966.