Since their discovery in the mid 1980s, fullerenes have caused a sensation. The tiny hollow spheres made of 60 carbon atoms, constructed out of pentagons and hexagons like miniature soccer balls, have unusual physical properties.
In the meantime, a variety of fullerene-containing materials have been developed. Now a new variant has been made: A Russian and Japanese team has produced the first material made of two-dimensional fullerene layers that acts like a metal. As the researchers report in the journal Angewandte Chemie, this new class of compounds could open a route toward novel superconducting materials.
All previous fullerene-containing crystals with metallic properties have been one- or three-dimensional structures and contained metal elements. Dmitri V. Konarev, Gunzi Saito, and their co-workers from Chernogolovka, Kyoto, and Nagoya had the ambition to make a metallic conducting fullerene “salt” containing two-dimensional fullerene layers. In addition, they wanted it to be free of metal ions, containing only the elements carbon, hydrogen, and nitrogen.
For this to work, three different components were needed: 1) fullerene anions, negatively charged “miniature soccer balls”; 2) positively charged organic counterions (cations); and 3) large neutral organic molecules. Component 2, the cations, are needed to maintain the right distribution of electrical charge within the material. The neutral compound 3 assures the correct spatial arrangement of the individual building blocks within the crystal structure.
The problem: fullerene anions in a crystal have a tendency to form pairs. In order for the material to behave as a metal, the fullerene anions need to be densely packed within their layer. Only when the geometry and size of the neutral partner are exactly right does this work. The team chose to use triptycene as the neutral component; this is an aromatic ring system whose shape is reminiscent of a three-bladed propeller. The organic cation they used has a cage-like structure.
The result is a crystal in which fullerene layers alternate with layers made of the two other partners. The fullerene layer has a honeycomb structure in which every tiny, negatively charged “soccer ball” has six adjacent neighbors. The fullerene layers are highly conducting like a metal—even down to temperatures near absolute zero (1.9 K), which is very unusual.
It should be possible to produce other materials in this class by varying the individual partners. The researches expect that this will produce materials with exotic electronic properties, such as novel superconductors or spin liquids, which are materials that show an unusual magnetic state at absolute zero.
Author: Dimitri Konarev, Russian Academy of Science, Moscow (Russia), mailto:email@example.com
Title: A Two-Dimensional Organic Metal Based on Fullerene
Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201001463
Dimitri Konarev | Angewandte Chemie
Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute
'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences