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

Heating quantum matter: A novel view on topology: Physicists demonstrate how heating up a quantum system can be used as a universal probe for exotic states of matter August 22nd, 2017

A Tougher Tooth: A new dental restoration composite developed by UCSB scientists proves more durable than the conventional material August 22nd, 2017

Nagoya physicists resolve long-standing mystery of structure-less transition: Nagoya University-led team of physicists use a synchrotron radiation X-ray source to probe a so-called 'structure-less' transition and develop a new understanding of molecular conductors August 21st, 2017

Tokai University research: Nanomaterial wrap for improved tissue imaging August 21st, 2017

Possible Futures

Heating quantum matter: A novel view on topology: Physicists demonstrate how heating up a quantum system can be used as a universal probe for exotic states of matter August 22nd, 2017

A Tougher Tooth: A new dental restoration composite developed by UCSB scientists proves more durable than the conventional material August 22nd, 2017

Nagoya physicists resolve long-standing mystery of structure-less transition: Nagoya University-led team of physicists use a synchrotron radiation X-ray source to probe a so-called 'structure-less' transition and develop a new understanding of molecular conductors August 21st, 2017

Tokai University research: Nanomaterial wrap for improved tissue imaging August 21st, 2017

Academic/Education

Two Scientists Receive Grants to Develop New Materials: Chad Mirkin and Monica Olvera de la Cruz recognized by Sherman Fairchild Foundation August 16th, 2017

Moving at the Speed of Light: University of Arizona selected for high-impact, industrial demonstration of new integrated photonic cryogenic datalink for focal plane arrays: Program is major milestone for AIM Photonics August 10th, 2017

Graduate Students from Across the Country Attend Hands-on NanoCamp: Prominent scientists Warren Oliver, Ph.D., and George Pharr, Ph.D., presented a weeklong NanoCamp for hand-picked graduate students across the United States July 26th, 2017

The Physics Department of Imperial College, London, uses the Quorum Q150T to deposit metals and ITO to make plasmonic sensors and electric contact pads July 13th, 2017

Memory Technology

Surprise discovery in the search for energy efficient information storage August 10th, 2017

Liquid electrolyte contacts for advanced characterization of resistive switching memories July 26th, 2017

Shining rings: A new material emits white light when exposed to electricity: New synthetic approach could spark development of other dynamic materials July 24th, 2017

Pulses of electrons manipulate nanomagnets and store information: Scientists use electron pulses to create and manipulate nanoscale magnetic excitations that can store data July 21st, 2017

Announcements

Heating quantum matter: A novel view on topology: Physicists demonstrate how heating up a quantum system can be used as a universal probe for exotic states of matter August 22nd, 2017

A Tougher Tooth: A new dental restoration composite developed by UCSB scientists proves more durable than the conventional material August 22nd, 2017

Nagoya physicists resolve long-standing mystery of structure-less transition: Nagoya University-led team of physicists use a synchrotron radiation X-ray source to probe a so-called 'structure-less' transition and develop a new understanding of molecular conductors August 21st, 2017

Tokai University research: Nanomaterial wrap for improved tissue imaging August 21st, 2017

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