Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study uncovers redox response properties of largest-ever polymeric o-phenylenes

16.11.2010
New findings by researchers at RIKEN and the Japan Science and Technology Agency (JST) have shed light on the remarkable electrochemical response properties of an elusive class of molecular helix structures, charting a new path in the design of molecular machines and devices.

Among the most ubiquitous structural motifs in nature, helices play an essential role in a wide range of biological processes. The capacity of certain helix structures to respond to external stimuli by changing shape, in particular, offers key insights in the design of functional molecular devices. As of yet, however, few such structures have been identified that respond to electrochemical inputs, one of the most important types of stimuli.

Now a class of helical structures has been found to do this, and more. o-Phenylenes are densely-packed chains of phenylene (C6H4) compounds linked together at their ortho positions by heavily-angled connections. Despite potentially rich conformational behavior, o-phenylenes are difficult to study and have been all but forgotten since their discovery more than 50 years ago.

In a paper in Nature Chemistry, the RIKEN/JST research group demonstrates a method for synthesizing polymeric o-phenylenes on scales never before observed, the largest reaching some 48 phenylene units. Problems of electrochemical instability which plagued earlier studies are solved by introducing a nitrogen group to the end of the o-phenylene chain, enabling first-ever exploration of o-phenylene oxidation-reduction response.

Experiments with the new o-phenylenes revealed intriguing results. In solution, the helices depart from their folded form to undergo rapid inversion between clockwise and anti-clockwise orientations, yet when they crystallize, they converge uniformly to only one orientation, in a rare process called chiral symmetry-breaking. Removal of a single electron, meanwhile, converts helices across the entire solution to a more compact form, slowing the inversion rate by a factor of more than 450.

Through its parallel to permanent and long-lasting memory, this unique form of conformational rigidity alterable by electrical inputs offers a completely new design concept for nanotechnology, opening new avenues for the design of molecular wires and other nano-scale devices.

For more information, please contact:

Dr. Takuzo Aida
Functional Soft Matter Research Group
RIKEN Advanced Science Institute
Tel: +81-(0)3-5841-7251 / Fax: +81-(0)3-5841-7310
Ms. Tomoko Ikawa (PI officer)
Global Relations Office
RIKEN
Tel: +81-(0)48-462-1225 / Fax: +81-(0)48-463-3687
Email: koho@riken.jp
Reference:
Eisuke Ohta, Hiroyasu Sato, Shinji Ando, Atsuko Kosaka, Takanori Fukushima, Daisuke Hashizume, Mikio Yamasaki, Kimiko Hasegawa, Azusa Muraoka, Hiroshi Ushiyama and Takuzo Aida. Redox-responsive molecular helices with highly condensed p –clouds. Nature Chemistry (2010). DOI: 10.1038/NCHEM.900

gro-pr | Research asia research news
Further information:
http://www.riken.jp
http://www.researchsea.com

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

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>