PDA

View Full Version : New device takes pictures of molecules


Name Lips
08-30-2009, 10:36 AM
http://cosmiclog.msnbc.msn.com/archive/2009/08/27/2046556.aspx


Naked molecule exposed
Posted: Thursday, August 27, 2009 8:10 PM by Alan Boyle

Scientists have traced the structure of a complete molecule in all its glory, using the sharpest pen ever devised: an atomic force microscope tipped with a single molecule of carbon monoxide.

The experiment, detailed in Friday's issue of the journal Science, could help open up a new frontier for molecular-scale circuitry and construction.

Researchers have been imaging molecules and their constituent atoms in crystals for decades, but the trick is to get a fine-resolution fix on the structure and behavior of an entire, self-contained molecule as it sits on a surface.

If you have the wrong stuff at the very tip of your probe, the very act of mapping the molecule can spoil the picture.

Leo Gross and his colleagues at IBM's Zurich Research Laboratory found that a carbon monoxide molecule (with its oxygen atom sticking straight out from the tip) produced "spectacular" images of the pentacene molecule. That's a well-studied type of hydrocarbon composed of five benzene rings interlocked in a row (C22H14).

The benzene rings showed up brightly in the atomic-scale images, just as predicted by theory. One of the images published in Science even showed several of the five-ring molecules scattered around a surface like nano-caterpillars.

The researchers said their results were so good because the carbon monoxide molecule could get incredibly close to the pentacene molecule without picking it up or moving it around. When they tried probes that were tipped in metals, such as gold or silver or copper, the pentacene molecule would move around before the tip came close enough to map the chemical forces holding the molecule together.

The IBM team concluded that non-contact atomic force microscopy can be a great way to see how molecules are put together, but only if the microscope's probe is tipped with the right stuff.

The next step is to probe differently constructed molecules to see how they react with various types of tips - and see which kinds of surfaces work best as a molecular-scale lab bench. The goal of all this is to devise a molecular construction toolkit, as well as methods for watching how the tools in the kit work together.

"Eventually we want to investigate using molecules for molecular electronics," Gross told Chemistry World. "We want to use molecules as wires or logic switches or elements."

Experts in nanotechnology have long dreamed of creating molecular-scale circuitry that could revolutionize the computer world. But Gross told EETimes that the revolution is still far off. "It will take at least 15 years to see molecular electronic applications," he said, "and it is by no means certain that we will succeed."

http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/090827-coslog-molecule-square-130p.standard.jpg
http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/090827-coslog-molecules-5p.standard.jpg

Wow.

Scarbonac
08-30-2009, 09:15 PM
http://cosmiclog.msnbc.msn.com/archive/2009/08/27/2046556.aspx


http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/090827-coslog-molecule-square-130p.standard.jpg
http://msnbcmedia.msn.com/j/MSNBC/Components/Photo/_new/090827-coslog-molecules-5p.standard.jpg

Wow.

:yes::yes::yes:

Trainz
08-30-2009, 10:57 PM
You mean to tell me that the last picture is NOT a computer reconstruction, but an actual picture of molecules???

Name Lips
08-30-2009, 10:59 PM
You mean to tell me that the last picture is NOT a computer reconstruction, but an actual picture of molecules???

That is correct.

Pigs in Space
08-31-2009, 10:39 PM
That is correct.

Why can't I see more molecules in the background, or foreground?

How come they're all aligned on their side, nice and purty like that?

Name Lips
08-31-2009, 10:58 PM
Why can't I see more molecules in the background, or foreground?

How come they're all aligned on their side, nice and purty like that?

This is just a series of guesses, but I'd wager that first off the experiment is done in a clean vacuum so there's no molecules floating around to mess up the scan.

It also looks like the special scanner/molecule/microscope thingie is simply passed back and forth over the target slowly. By tracking when the tip interacts with the molecule under it, they can compile an image. It's not a photograph - you're not seeing light reflecting off a molecule.

I'd guess that the pale gray background is either too far from the tip to image its own molecules, or constructed from molecules that don't interact in a significant way with the imager, thus appearing "invisible."

I'd also guess that they took hundreds of scans, and released the best looking ones to the press. So looking all lined up and neatly arranged is probably just a side effect of having the bad looking images thrown out.

Harry
08-31-2009, 11:20 PM
I'm still wondering what insane Google search lead to you posting threads in one night of both naked molecules and the revival of burlesque. Coincidence? or.... conspiracy? :boggle:

spence.smith
03-17-2010, 12:41 AM
The closest you can come to taking a picture of atoms that make up molecules is an electron microscope. This, however only plots a sort of map of where the atoms are located by sending electrons through the material and measuring their offset. So, short answer... No, molecules are too tiny to be photographed.

There are ways to obtain "images" of molecules that are not a COMPLETE standstill (so called zero-point vibrations rule that out), but they're still enough to image. It isn't a "picture" as in a photograph, but an image can be reconstructed using the techniques of atomic force microscopy and - less directly - scanning tunneling microscopy. Crystallography is used to determine the structure of molecules in crystals, and crystallographic methods (especially x-ray crystallography) are the means by which we have the most precise knowledge of molecular structure.

Harry
03-17-2010, 01:06 AM
The closest you can come to taking a picture of atoms that make up molecules is an electron microscope. This, however only plots a sort of map of where the atoms are located by sending electrons through the material and measuring their offset. So, short answer... No, molecules are too tiny to be photographed.

There are ways to obtain "images" of molecules that are not a COMPLETE standstill (so called zero-point vibrations rule that out), but they're still enough to image. It isn't a "picture" as in a photograph, but an image can be reconstructed using the techniques of atomic force microscopy and - less directly - scanning tunneling microscopy. Crystallography is used to determine the structure of molecules in crystals, and crystallographic methods (especially x-ray crystallography) are the means by which we have the most precise knowledge of molecular structure.

How interesting.

http://answers.yahoo.com/question/index?qid=20090721190757AA5Yh8e

Trainz
03-17-2010, 01:17 AM
Woah...

Your intarweeb-fu is impressive.

I'm impressed.

:shock:

Schizm
03-17-2010, 01:52 AM
Harry, quit pointing out that the noob is plagarizing. ;)

The Winslow
03-17-2010, 07:38 AM
Spambots are so weird now.

Hatter
03-17-2010, 11:20 AM
Spambots are so weird now.

Indeed. I had to actually go check to be sure (I have sigs turned off), but you're right.

Ancalagon
03-17-2010, 09:24 PM
If that's a spam bot... I'm impressed :shock: