Featured Research

from universities, journals, and other organizations

Molecules form 2-D patterns never before observed: Nanoscience experiments produce elusive 5-vertex tilings

Date:
August 8, 2013
Source:
Technische Universitaet Muenchen
Summary:
Tessellation patterns that have fascinated mathematicians since Kepler worked out their systematics 400 years ago -- and that more recently have caught the eye of artists and crystallographers -- can now be seen in the laboratory. They first took shape on a surface more perfectly two-dimensional than any sheet of paper, a single layer of atoms and molecules atop an atomically smooth substrate. Physicists coaxed these so-called Kepler tilings "onto the page" through guided self-assembly of nanostructures.

The 2-D tessellation pattern known as the "semiregular snub square tiling" stands out clearly in this image, which combines scanning tunneling microscopy with computer graphics. The pattern, observed in a surface architecture just one molecule thick, was formed by self-assembly of linear organic linkers, imaged as rods, and lanthanide cerium centers, visualized as bright protrusions. The area shown measures less than 25 nanometers across.
Credit: Barth Lab, copyright TUM

Tessellation patterns that have fascinated mathematicians since Johannes Kepler worked out their systematics 400 years ago -- and that more recently have caught the eye of both artists and crystallographers -- can now be seen in the laboratory. They first took shape on a surface more perfectly two-dimensional than any sheet of writing paper, a single layer of atoms and molecules atop an atomically smooth substrate. Physicists coaxed these so-called Kepler tilings "onto the page" through guided self-assembly of nanostructures.

The experiments were carried out by postdoctoral researcher David Ecija, PhD candidate Jose Ignacio Urgel and colleagues in the Physics Department of Technische Universitaet Muenchen (TUM), in collaboration with scientists in Karlsruhe and Zurich. They reported their findings in the Proceedings of the National Academy of Sciences.

Results open a new line of research

Organic molecules equipped with functional groups to express distinct linkages to metal atoms were deposited onto a smooth silver substrate under vacuum conditions. Subsequently the organic layer on this platform was exposed to an atomic flux of the lanthanide cerium. At a certain ratio of cerium atoms to molecules, self-assembly produced a symmetrical complex 2-D pattern described originally by Kepler and known today as the snub square tiling. Clearly identifiable through scanning tunneling microscopy was a recurring, five-vertex connecting element less than one nanometer across, a cerium-ligand coordination unit.

That the snub square tiling pattern had never been fabricated and seen at the molecular level by exploiting self-assembly protocols was interesting in itself. Beyond that, the physicists explain, every new surface architecture could potentially open the way to novel physics and chemistry, and until now five-vertex structures have proven elusive. In particular, the fact that the lanthanide element cerium played such a key role marks this as the beginning of a new line of research.

This is the first time the TUM researchers -- members of Prof. Johannes Barth's Institute for Molecular Nanoscience and Chemical Physics of Interfaces -- have coordinated molecules with a lanthanide, and the first time anyone has done this in 2-D. "And lanthanides are special," David Ecija explains. "They have very intriguing optical, magnetic, and chemical properties that could be interesting for nanoscience, and possibly also for nanotechnology. Now we have a new playground for research with the lanthanides, and beyond."


Story Source:

The above story is based on materials provided by Technische Universitaet Muenchen. Note: Materials may be edited for content and length.


Journal Reference:

  1. D. Ecija, J. I. Urgel, A. C. Papageorgiou, S. Joshi, W. Auwarter, A. P. Seitsonen, S. Klyatskaya, M. Ruben, S. Fischer, S. Vijayaraghavan, J. Reichert, J. V. Barth. Five-vertex Archimedean surface tessellation by lanthanide-directed molecular self-assembly. Proceedings of the National Academy of Sciences, 2013; 110 (17): 6678 DOI: 10.1073/pnas.1222713110

Cite This Page:

Technische Universitaet Muenchen. "Molecules form 2-D patterns never before observed: Nanoscience experiments produce elusive 5-vertex tilings." ScienceDaily. ScienceDaily, 8 August 2013. <www.sciencedaily.com/releases/2013/08/130808123823.htm>.
Technische Universitaet Muenchen. (2013, August 8). Molecules form 2-D patterns never before observed: Nanoscience experiments produce elusive 5-vertex tilings. ScienceDaily. Retrieved September 2, 2014 from www.sciencedaily.com/releases/2013/08/130808123823.htm
Technische Universitaet Muenchen. "Molecules form 2-D patterns never before observed: Nanoscience experiments produce elusive 5-vertex tilings." ScienceDaily. www.sciencedaily.com/releases/2013/08/130808123823.htm (accessed September 2, 2014).

Share This




More Matter & Energy News

Tuesday, September 2, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Google Teases India Event, Possible Android One Reveal

Google Teases India Event, Possible Android One Reveal

Newsy (Sep. 1, 2014) — Google has announced a Sept. 15 event in India during which they're expected to reveal their Android One phones. Video provided by Newsy
Powered by NewsLook.com
Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) — Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) — Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) — Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
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:
from the past week

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