Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clusters of Aluminum Atoms Found to Have Properties of Other Elements Reveal a New Form of Chemistry

14.01.2005


Artist’s rendition of an aluminum-iodine "Superatom" identified by the Castleman group at Penn State and the Khanna group at Virginia Commonwealth University. Credit: D.E. Bergeron, P.J. Roach, A.W. Castleman, N.O. Jones, and S.N. Khanna


A research team has discovered clusters of aluminum atoms that have chemical properties similar to single atoms of metallic and nonmetallic elements when they react with iodine. The discovery opens the door to using ’superatom chemistry’ based on a new periodic table of cluster elements to create unique compounds with distinctive properties never seen before. The results of the research, headed jointly by Shiv N. Khanna, professor of physics at Virginia Commonwealth University and A. Welford Castleman Jr., the Evan Pugh Professor of Chemistry and Physics and the Eberly Family Distinguished Chair in Science at Penn State University, will be reported in the 14 January 2005 issue of the journal Science.

"Depending on the number of aluminum atoms in the cluster, we have demonstrated ’superatoms’ exhibiting the properties of either halogens or alkaline earth metals," says Castleman. "This result suggests the intriguing potential of this chemistry in nanoscale synthesis." The discovery could have practical applications in the fields of medicine, food production and photography.

The researchers examined the chemical properties, electronic structure, and geometry of aluminum clusters both theoretically and experimentally in chemical compounds with iodine atoms. They found that a cluster of 13 aluminum atoms behaves like a single iodine atom, while a cluster of 14 aluminum atoms behaves like an alkaline earth atom. "The discovery of these new iodine compounds, which include aluminum clusters, is critical because it reveals a new form of ’superatom’ chemistry," said Khanna. "In the future, we may apply this chemistry, building on our previous knowledge, to create new materials for energy applications and even medical devices."


To make their discovery, the research team replaced iodine atoms with the aluminum clusters in naturally occurring chains or networks of iodine atoms and molecules known as polyiodides. When the researchers substituted the iodine atom with the aluminum cluster, Al13, they observed that the entire chemistry of the compound changed--causing the other iodine molecules to break apart and bind individually to the cluster. The researchers then were able to bind 12 iodine atoms to a single Al13 cluster, forming a completely new class of polyiodides. "Our production of such a species is a stirring development that may lead to new compounds with a completely new class of chemistry and applications," says Castleman. "Along with the discovery that Al14 clusters appear to behave similarly to alkaline earth atoms when combined with iodine, these new results give further evidence that we are really on our way to the development of a periodic table of the ’cluster elements’."

The researchers conducted experimental reactivity studies that indicate that certain aluminum-cluster superatoms are highly stable by nature. The team’s related theoretical investigations reveal that the enhanced stability of these superatoms is associated with a balance in their atomic and electronic states. While the clusters resemble atoms of other elements in their interactions, their chemistry is unique, creating stable compounds with bonds that are not identical to those of single atoms.

Using stable clusters provides a possible route to an adaptive chemistry that introduces the aluminum-cluster species into nanoscale materials, tailoring them to create desirable properties. "The flexibility of an Al13 cluster to act as an iodine atom shows that superatoms can have synthetic utility, providing an unexplored ’third dimension’ to the traditional periodic table of elements," said Khanna. "Applications using Al13 clusters instead of iodine in polymers may lead to the development of improved conducting materials. Assembling Al13I units may provide aluminum materials that will not oxidize, and may help overcome a major problem in fuels that burn aluminum particles."

The theoretical investigations for this project were conducted by Khanna with N.O. Jones, a graduate student in the physics department at Virginia Commonwealth University, and the experimental work was conducted by Castleman with Denis Bergeron and Patrick J. Roach, graduate students in the chemistry department at Penn State.

This research was supported by the U. S. Air Force Office of Scientific Research and the U. S. Department of Energy.

Barbara K. Kennedy | EurekAlert!
Further information:
http://www.psu.edu
http://www.vcu.edu

More articles from Life Sciences:

nachricht Sensory Perception Is Not a One-Way Street
17.10.2018 | Eberhard Karls Universität Tübingen

nachricht Sex or food? Decision-making in single-cell organisms
17.10.2018 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Goodbye, silicon? On the way to new electronic materials with metal-organic networks

Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz (Germany) together with scientists from Dresden, Leipzig, Sofia (Bulgaria) and Madrid (Spain) have now developed and characterized a novel, metal-organic material which displays electrical properties mimicking those of highly crystalline silicon. The material which can easily be fabricated at room temperature could serve as a replacement for expensive conventional inorganic materials used in optoelectronics.

Silicon, a so called semiconductor, is currently widely employed for the development of components such as solar cells, LEDs or computer chips. High purity...

Im Focus: Storage & Transport of highly volatile Gases made safer & cheaper by the use of “Kinetic Trapping"

Augsburg chemists present a new technology for compressing, storing and transporting highly volatile gases in porous frameworks/New prospects for gas-powered vehicles

Storage of highly volatile gases has always been a major technological challenge, not least for use in the automotive sector, for, for example, methane or...

Im Focus: Disrupting crystalline order to restore superfluidity

When we put water in a freezer, water molecules crystallize and form ice. This change from one phase of matter to another is called a phase transition. While this transition, and countless others that occur in nature, typically takes place at the same fixed conditions, such as the freezing point, one can ask how it can be influenced in a controlled way.

We are all familiar with such control of the freezing transition, as it is an essential ingredient in the art of making a sorbet or a slushy. To make a cold...

Im Focus: Micro energy harvesters for the Internet of Things

Fraunhofer IWS Dresden scientists print electronic layers with polymer ink

Thin organic layers provide machines and equipment with new functions. They enable, for example, tiny energy recuperators. In future, these will be installed...

Im Focus: Dynamik einzelner Proteine

Neue Messmethode erlaubt es Forschenden, die Bewegung von Molekülen lange und genau zu verfolgen

Das Zusammenspiel aus Struktur und Dynamik bestimmt die Funktion von Proteinen, den molekularen Werkzeugen der Zelle. Durch Fortschritte in der...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Conference to pave the way for new therapies

17.10.2018 | Event News

Berlin5GWeek: Private industrial networks and temporary 5G connectivity islands

16.10.2018 | Event News

5th International Conference on Cellular Materials (CellMAT), Scientific Programme online

02.10.2018 | Event News

 
Latest News

Robot-assisted sensor system for quality assurance of press-hardened components

17.10.2018 | Trade Fair News

Sensory Perception Is Not a One-Way Street

17.10.2018 | Life Sciences

Plant Hormone Makes Space Farming a Possibility

17.10.2018 | Agricultural and Forestry Science

VideoLinks
Science & Research
Overview of more VideoLinks >>>