Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > This Way and That

Pillars of salts: By combining planar cations and planar anionic structures based on ­-conjugated acyclic Dipyrroles containing an anion, charge-by-charge assemblies could be formed (see picture). Not only crystals but also soft materials, such as supramolecular gels and thermotropic liquid crystals, could be made by this method.
Pillars of salts: By combining planar cations and planar anionic structures based on ­-conjugated acyclic Dipyrroles containing an anion, charge-by-charge assemblies could be formed (see picture). Not only crystals but also soft materials, such as supramolecular gels and thermotropic liquid crystals, could be made by this method.

Abstract:
Alternating stacks of planar cations and planar dipyrrole-containing anions provides concept for formation of new materials

This Way and That

Weinheim, Germany | Posted on December 10th, 2010

Pyrroles, which are rings containing one nitrogen and four carbon atoms, are essential components of our red hemoglobin as well as the green chlorophyll in plants. Japanese researchers led by Hiromitsu Maeda at Risumeikan University have now also used this molecular motif in the construction of new nanostructured materials: They combined planar pyrrole-containing negatively charged complexes with similarly planar, positively charged organic ions. As the scientists report in the journal Angewandte Chemie, they were able to produce fibers and soft materials, such as supramolecular gels and liquid crystals.

Salts consist of cations and anionsŚpositively and negatively charged particles. Most salts organize themselves into ordered crystals that are held together through the electrostatic attraction between the oppositely charged ions. However, there are also ionic liquids, which are salts that exist as melts at room temperature. The size and geometry of the ions involved prevent the formation of a strong crystal lattice. Ionic liquid crystals are another interesting class of materials. Liquid crystals are fluid like a liquid, though the particles in them are arranged in an ordered state. In addition, there are other materials that are more organized but whose components maintain a certain degree of mobility. These are of interest for the development of ferroelectric memory devices.

The Japanese researchers selected planar ions to build up self-organized materials in which the charged components are stacked in an alternating fashion. The first component is a planar complex made from a small inorganic ion and an organic receptor (receptor-anion complex). The critical structural element of the receptor contains two pyrroles bound into what is known as a ­-conjugated environment. This means that some of the electrons are freely mobile as an "electron cloud" over a large area of the molecule. The ligand surrounds the anion on three sides. The second component is a disk-shaped organic cation made from an aromatic ring system, which also has an electron cloud. Because of the electrostatic attraction between oppositely charged ions, and also attractive interactions between the electron clouds, these anions and cations always stack themselves into alternating columnar units.

Depending on the type of additional side-groups on the components, the columns organize into various structures, such as fibers, supramolecular gels, or liquid crystals. Such alternating stacks of oppositely charged components (charge-by-charge assembly) has proven to be a successful concept for the production of novel materials from organic ions.

Author: Hiromitsu Maeda, Ritsumeikan University, Kusatsu (Japan), www.ritsumei.ac.jp/pharmacy/maeda/frame-10en.html

Title: Oriented Salts: Dimension-Controlled Assemblies from Planar Receptor-Anion Complexes

Angewandte Chemie International Edition 2010, 49, No. 52, 10079-10083, Permalink to the article: dx.doi.org/10.1002/anie.201006356

####

For more information, please click here

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

Device to control 'color' of electrons in graphene provides path to future electronics August 31st, 2016

Graphene key to growing 2-dimensional semiconductor with extraordinary properties August 30th, 2016

University of Akron researchers find thin layers of water can become ice-like at room temperature: Results could lead to an assortment of anti-friction solutions August 30th, 2016

Nanocatalysis for organic chemistry: This research article by Dr. Qien Xu et al. is published in Current Organic Chemistry, Volume 20, Issue 19, 2016 August 30th, 2016

Possible Futures

Device to control 'color' of electrons in graphene provides path to future electronics August 31st, 2016

Graphene key to growing 2-dimensional semiconductor with extraordinary properties August 30th, 2016

Nanocatalysis for organic chemistry: This research article by Dr. Qien Xu et al. is published in Current Organic Chemistry, Volume 20, Issue 19, 2016 August 30th, 2016

Continuous roll-process technology for transferring and packaging flexible LSI August 29th, 2016

Academic/Education

AIM Photonics Announces Release of Process Design Kit (PDK) for Integrated Silicon Photonics Design August 25th, 2016

Nanotech Security Featured by Simon Fraser University: Company's Anti-Counterfeiting Technology Developed With the Help of University's 4D LABS Materials Research Institute August 21st, 2016

W.M. Keck Foundation awards Cal State LA a $375,000 research and education grant August 4th, 2016

Thomas Swan and NGI announce unique partnership July 28th, 2016

Memory Technology

Magnetic atoms arranged in neat rows: FAU physicists enable one-dimensional atom chains to grow August 5th, 2016

New metamaterials can change properties with a flick of a light-switch: Material can lead to new optical devices August 3rd, 2016

Making magnets flip like cats at room temperature: Heusler alloy NiMnSb could prove valuable as a new material for digital information processing and storage July 25th, 2016

Research team led by NUS scientists develop plastic flexible magnetic memory device: Novel technique to implant high-performance magnetic memory chip on a flexible plastic surface without compromising performance July 21st, 2016

Announcements

Device to control 'color' of electrons in graphene provides path to future electronics August 31st, 2016

Graphene key to growing 2-dimensional semiconductor with extraordinary properties August 30th, 2016

University of Akron researchers find thin layers of water can become ice-like at room temperature: Results could lead to an assortment of anti-friction solutions August 30th, 2016

Nanocatalysis for organic chemistry: This research article by Dr. Qien Xu et al. is published in Current Organic Chemistry, Volume 20, Issue 19, 2016 August 30th, 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