Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > This Way and That

Pillars of salts: By combining planar cations and planar anionic structures based on š-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 š-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 anions—positively 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 š-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

Non-Enzyme Sensor Determines Level of Blood Sugar July 29th, 2015

Flexible Future of Point-of-Care Disease Diagnostic July 29th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Detecting small metallic contaminants in food via magnetization: A practical metallic-contaminant detecting system using three high-Tc RF superconducting quantum interference devices (SQUIDs) July 29th, 2015

Possible Futures

Smaller, faster, cheaper: A new type of modulator for the future of data transmission July 27th, 2015

Researchers predict material with record-setting melting point July 27th, 2015

Global Corrosion Resistant Nano Coatings Market To 2015: Acute Market Reports July 27th, 2015

Global Zinc oxide nanopowders Industry 2015: Acute Market Reports July 25th, 2015

Academic/Education

Deben reports on the use of their CT500 in the X-ray microtomography laboratory at La Trobe University, Melbourne, Australia July 22nd, 2015

JPK reports on the use of SPM in the Messersmith Group at UC Berkeley looking at biologically inspired polymer adhesives. July 21st, 2015

Renishaw adds Raman analysis to Scanning Electron Microscopy at the University of Sydney, Australia July 9th, 2015

Oxford Instruments’ TritonXL Cryofree dilution refrigerator selected for the Oxford NQIT Quantum Technology Hub project June 30th, 2015

Memory Technology

Controlling phase changes in solids: Controlling phase changes in solids July 29th, 2015

Reshaping the solar spectrum to turn light to electricity: UC Riverside researchers find a way to use the infrared region of the sun's spectrum to make solar cells more efficient July 27th, 2015

Spintronics: Molecules stabilizing magnetism: Organic molecules fixing the magnetic orientation of a cobalt surface/ building block for a compact and low-cost storage technology/ publication in Nature Materials July 25th, 2015

Better memory with faster lasers July 14th, 2015

Announcements

Non-Enzyme Sensor Determines Level of Blood Sugar July 29th, 2015

Flexible Future of Point-of-Care Disease Diagnostic July 29th, 2015

Meet the high-performance single-molecule diode: Major milestone in molecular electronics scored by Berkeley Lab and Columbia University team July 29th, 2015

Detecting small metallic contaminants in food via magnetization: A practical metallic-contaminant detecting system using three high-Tc RF superconducting quantum interference devices (SQUIDs) July 29th, 2015

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