Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biting its Own Tail

20.04.2010
Nanocontainer with an integrated switch

The ouroboros (ancient Greek for “tail devourer”) is a motif found in many cultures: a snake biting its own tail, it symbolizes eternity and cycles. Julius Rebek, Jr. and Fabien Durola (The Scripps Research Institute, La Jolla, USA) have now constructed a molecular tail devourer, and have named this new class of compound “ouroborand”. As the researchers report in the journal Angewandte Chemie, their tail-biter is a molecular “machine”, which functions as a nanocontainer with a built-in switch that regulates access to the cavity.

Molecular machines and nanoscopic components imitate—at least theoretically—the functions of their macroscopic analogues. For example, nanoscopic capsules can act as reaction vessels, molecules with parts that rotate relative to each other to imitate rotors, and various types of on/off switches.

The ouroborand made by the American research duo is a molecule consisting of multiple parts. A cavity that can take up guest molecules serves as a container. At its edge, the container has a switchable rotor (a bipyridyl unit) to which an intramolecular guest is attached like a hand at the end of a coupling arm of appropriate length. The rotor is turned so that the hand at the end of the arm sits inside the container. The container is thus blocked and not accessible to other molecules; it is switched to closed. In this conformation it is reminiscent of a snake that is swallowing its own tail, the ouroboros.

If zinc ions are added to the solution, they trigger a switching mechanism: the rotor has two binding sites for zinc ions. In order for both to bind an ion, the rotor must make a half-turn. The coupling arm turns with it, which causes the hand to be pulled out of the container. The vessel is now free and accessible to other molecules; it is switched to open. If the zinc ions are taken back out of the solution, the rotor then turns back to the starting position and the hand throws the foreign molecule back out of the container.

Author: Julius Rebek, Jr., Scripps Research Institute, La Jolla (USA), http://www.scripps.edu/skaggs/rebek/

Title: The Ouroborand: A Cavitand with a Coordination-Driven Switching Device

Angewandte Chemie International Edition 2010, 49, No. 18, 3189–3191, Permalink to the article: http://dx.doi.org/10.1002/anie.200906753

Julius Rebek, Jr. | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://www.scripps.edu/skaggs/rebek/

More articles from Life Sciences:

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Scientist invents way to trigger artificial photosynthesis to clean air

26.04.2017 | Materials Sciences

Ammonium nitrogen input increases the synthesis of anticarcinogenic compounds in broccoli

26.04.2017 | Agricultural and Forestry Science

SwRI-led team discovers lull in Mars' giant impact history

26.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>