Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Biting its Own Tail

Molecular switch: The ouroborand coordinates an internal side chain in its cavity, just as it were swallowing its own tail. The presence or absence of zinc(II) in solution switches the cavity between open and closed states to external guests (see scheme: deep blue sphere: Zn).
Molecular switch: The ouroborand coordinates an internal side chain in its cavity, just as it were swallowing its own tail. The presence or absence of zinc(II) in solution switches the cavity between open and closed states to external guests (see scheme: deep blue sphere: Zn).

Abstract:
Nanocontainer with an integrated switch

Biting its Own Tail

Weinheim, Germany | Posted on April 20th, 2010

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), 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: dx.doi.org/10.1002/anie.200906753

####

About Angewandte Chemie
Wiley InterScience (www.interscience.wiley.com) provides access to over 3 million articles across nearly 1500 journals and 7000 Online Books and major reference works. It also holds industry leading databases such as The Cochrane Library, chemistry databases and the acclaimed Current Protocols laboratory manuals.

For more information, please click here

Contacts:
Editorial office


Amy Molnar (US)


Jennifer Beal (UK)


Alina Boey (Asia)

Copyright © Angewandte Chemie

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Tiny packages may pack powerful treatment for brain tumors: Nanocarrier provides efficient delivery of chemotherapeutic drug May 23rd, 2016

Two-stage nanoparticle delivery of piperlongumine and TRAIL anti-cancer therapy May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

Graphene makes rubber more rubbery May 23rd, 2016

Molecular Machines

Little ANTs: Researchers build the world's tiniest engine May 3rd, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Physicists build engine consisting of one atom: World's smallest heat engine uses just a single particle April 17th, 2016

Revealing the fluctuations of flexible DNA in 3-D: First-of-their-kind images by Berkeley Lab-led research team could aid in use of DNA to build nanoscale devices March 31st, 2016

Announcements

Physicists create first metamaterial with rewritable magnetic ordering May 23rd, 2016

Tiny packages may pack powerful treatment for brain tumors: Nanocarrier provides efficient delivery of chemotherapeutic drug May 23rd, 2016

Two-stage nanoparticle delivery of piperlongumine and TRAIL anti-cancer therapy May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic