Featured Research

from universities, journals, and other organizations

Researchers take a look inside molecules

Date:
August 22, 2010
Source:
Helmholtz Association of German Research Centres
Summary:
Looking at individual molecules through a microscope is part of nanotechnologists' everyday lives. However, it has so far been difficult to observe atomic structures inside organic molecules. In a new study, researchers explain their novel method, which enables them to take an "X-ray view" inside molecules. The method may facilitate the analysis of organic semiconductors and proteins.

The Juelich method makes it possible to resolve molecule structure where only a blurred cloud was visible before.
Credit: Forschungszentrum Jülich

Looking at individual molecules through a microscope is part of nanotechnologists' everyday lives. However, it has so far been difficult to observe atomic structures inside organic molecules. In a new study published in Physical Review Letters, Juelich researchers explain their novel method, which enables them to take an "X-ray view" inside molecules. The method may facilitate the analysis of organic semiconductors and proteins.

Related Articles


For their look into the nanoworld, the Jülich researchers used a scanning tunneling microscope. Its thin metal tip scans the specimen surface like the needle of a record player and registers the atomic irregularies and differences of approximately one nanometre (a billionth of a metre) with minuscule electric currents. However, even though the tip of the microscope only has the width of an atom, it has not been able so far to take a look inside molecules.

"In order to increase the sensitivity for organic molecules, we put a sensor and signal transducer on the tip," says Dr. Ruslan Temirov. Both functions are fulfilled by a small molecule made up of two deuterium atoms, also called heavy hydrogen. Since it hangs from the tip and can be moved, it follow the contours of the molecule and influences the current flowing from the tip of the microscope. One of the first molecules studied by Temirov and co-workers was the perylene tetracarboxylic dianhydride compound. It consists of 26 carbon atoms, eight hydrogen atoms and six oxygen atoms forming seven interconnected rings. Earlier images only showed a spot with a diameter of approximately one nanometre and without any contours. Much like an X-ray image, the Jülich scanning tunneling microscope shows the molecule's honeycombed inner structure, which is formed by the rings.

"It's the remarkable simplicity of the method that makes it so valuable for future research," says Prof. Stefan Tautz, Director at the Institute of Bio- and Nanosystems at Forschungszentrum Jülich. The Jülich method has been filed as a patent and can easily be used with commercial scanning tunnelling microscopes. "The spatial dimensions inside molecules can now be determined within a few minutes, and the preparation of the specimen is based predominantly on standard techniques," says Tautz. In the next step, the Jülich scientists are planning to calibrate the measured current intensity as well. If they are successful, the measured current intensities may allow the type of atoms to be directly determined.

After publishing initial images produced with the new method in 2008, the research group of Tautz and Temirov has now been able to explain the quantum mechanical principle of operation of the deuterium at the tip of the microscope. Their results were supported by computer-assisted calculations by the working group of Prof. Michael Rohlfing at the University of Osnabrück. The so-called short-range Pauli repulsion is a quantum-physical force between the deuterium and the molecule which modulates the conductivity and allows us to measure the fine structures very sensitively.

The Jülich method can be used to measure the structure and charge distribution of flat molecules which can be used as organic semiconductors or as part of fast and efficient future electronic devices. Large three-dimensional biomolecules such as proteins can be examined as soon as the techniques have been refined.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. C. Weiss, C. Wagner, C. Kleimann, M. Rohlfing, F. Tautz, R. Temirov. Imaging Pauli Repulsion in Scanning Tunneling Microscopy. Physical Review Letters, 2010; 105 (8): 086103 DOI: 10.1103/PhysRevLett.105.086103

Cite This Page:

Helmholtz Association of German Research Centres. "Researchers take a look inside molecules." ScienceDaily. ScienceDaily, 22 August 2010. <www.sciencedaily.com/releases/2010/08/100820072031.htm>.
Helmholtz Association of German Research Centres. (2010, August 22). Researchers take a look inside molecules. ScienceDaily. Retrieved March 29, 2015 from www.sciencedaily.com/releases/2010/08/100820072031.htm
Helmholtz Association of German Research Centres. "Researchers take a look inside molecules." ScienceDaily. www.sciencedaily.com/releases/2010/08/100820072031.htm (accessed March 29, 2015).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Inspectors Found Faulty Work Before NYC Blast

Inspectors Found Faulty Work Before NYC Blast

AP (Mar. 27, 2015) — An hour before an apparent gas explosion sent flames soaring and debris flying at a Manhattan apartment building, injuring 19 people, utility company inspectors decided the work being done there was faulty. (March 27) Video provided by AP
Powered by NewsLook.com
Facebook Building Plane-Sized Drones For Global Internet

Facebook Building Plane-Sized Drones For Global Internet

Newsy (Mar. 27, 2015) — Facebook on Thursday revealed more details about its Internet-connected drone project. The drone is bigger than a 737, but lighter than a car. Video provided by Newsy
Powered by NewsLook.com
Robot Returns from International Space Station and Sets Two Guinness World Records

Robot Returns from International Space Station and Sets Two Guinness World Records

Reuters - Light News Video Online (Mar. 27, 2015) — The companion robot "Kirobo" returns to earth from the International Space Station and sets two Guinness World Records. Sharon Reich reports. Video provided by Reuters
Powered by NewsLook.com
Residents Witness Building Explosion, Collapse

Residents Witness Building Explosion, Collapse

AP (Mar. 26, 2015) — Witnesses recount the sites and sounds of a massive explosion and subsequent building collapse in the heart of Manhattan&apos;s trendy East Village on Thursday. (March 26) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins