Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Perfect Ribbons

Closing the zipper: A method for the bottom-up organic synthesis of defect-free graphene nanoribbons in solution has been developed. Polyphenylene precursors with a unique kinked backbone enabled full cyclodehydrogenation in a single reaction step by an intramolecular Scholl reaction with FeCl3.
Closing the zipper: A method for the bottom-up organic synthesis of defect-free graphene nanoribbons in solution has been developed. Polyphenylene precursors with a unique kinked backbone enabled full cyclodehydrogenation in a single reaction step by an intramolecular Scholl reaction with FeCl3.

Abstract:
Long and narrow, free of defects, and soluble: graphene nanoribbons by bottom-up synthesis

Perfect Ribbons

Weinheim, Germany | Posted on February 7th, 2011

Electronic components based on graphene could render our current silicon-based electronics obsolete. Graphene, a more recently discovered form of carbon, consists of two-dimensional sheets of aromatic six-membered carbon rings in a honeycomb arrangement. In contrast to extended graphene layers, narrow graphene nanoribbons have semiconducting properties and could thus be candidates for electronic applications. Klaus Müllen and a team from the Max Planck Institute for Polymer Research in Mainz have now introduced a new method for the synthesis of long, narrow graphene ribbons with defined dimensions in the journal Angewandte Chemie.

Previously, graphene ribbons were mainly cut out of larger graphene sheets or were obtained by slitting open carbon nanotubes lengthwise. However, with these methods it is impossible to produce ribbons that have a precisely established ratio of width to length as well as defined edges. These details are important because they determine the electronic properties of the ribbons. The search has thus been on for a method that allows controlled production of very narrow graphene ribbons—an extremely difficult challenge. The German researchers working with Müllen are now well on the way to overcome it. They are not starting with large structures to cut up (top-down); instead they are building their ribbons from smaller components (bottom-up).

The building blocks selected by Müllen and his team are long chains of aromatic six-membered carbon rings called polyphenlyenes. In contrast to previous approaches, they did not produce straight chains; instead they made them with a flexible, zigzagging, bent backbone. Furthermore, they attached hydrocarbon side-chains to the backbone to increase the solubility in organic solvents, which allows the compounds to be synthesized and processed in solution.

The next step is a reaction that splits off hydrogen (dehydrogenation). This causes a ring-closing reaction in each pointy tip of the zigzag, forming a new aromatic six-membered carbon ring that shares a side with three neighboring rings—the chain transforms in to a narrow ribbon.

In this way, the team was able to produce a series of different nanoribbons with lengths reaching over 40 nm. The width of the ribbon was defined by the size of the "points" of the polyphenylene precursor. The resulting ribbons are free of defects and soluble in common organic solvents.

"We have been the first to demonstrate that structural perfection can be achieved by the classical bottom-up synthesis of defined graphene nanoribbons," says Müllen. "The solubility of the ribbons is an important requirement for the large-scale production of electronic components."

Author: Klaus Müllen, Max-Planck-Institut für Polymerforschung, Mainz (Germany), www.mpip-mainz.mpg.de/groups/muellen/director

Title: Graphene Nanoribbons by Chemists: Nanometer-Sized, Soluble, and Defect-Free

Angewandte Chemie International Edition, Permalink to the article: dx.doi.org/10.1002/anie.201006593

####

For more information, please click here

Copyright © Angewandte Chemie International Edition

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

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

A new technique to make drugs more soluble August 28th, 2015

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 2015

Academic/Education

Announcing Oxford Instruments and School of Physics signing a Memorandum of Understanding August 26th, 2015

Kwansei Gakuin University in Hyogo, Japan, uses Raman microscopy to study crystallographic defects in silicon carbide wafers August 25th, 2015

JPK reports on the use of a NanoWizard® AFM-SECM system at the Université Paris Diderot looking at nanoscale biostructures August 18th, 2015

Rice, Penn State open center for 2-D coatings: National Science Foundation selects universities to develop atom-thin materials with industry partners August 13th, 2015

Nanotubes/Buckyballs/Fullerenes

Developing Component Scale Composites Using Nanocarbons August 26th, 2015

Southampton scientists find new way to detect ortho-para conversion in water August 25th, 2015

Revolutionary MIT-Developed Nanotechnology Company Showcases at CAMX in Dallas August 20th, 2015

Engineering a better 'Do: Purdue researchers are learning how August 4th, 2015

Announcements

Small but heading for the big time: Nanobiotix half year results for the six months ended 30 June 2015, in line with expectations: Major clinical achievements and corporate developments August 28th, 2015

A new technique to make drugs more soluble August 28th, 2015

Nanocatalysts improve processes for the petrochemical industry August 28th, 2015

Nanolab Technologies LEAPS Forward with High-Performance Analysis Services to the World: Nanolab Orders Advanced Local Electrode Atom Probe (LEAP®) Microscope from CAMECA Unit of AMETEK Materials Analysis Division August 27th, 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







Car Brands
Buy website traffic