Featured Research

from universities, journals, and other organizations

Silver-rich Lumps: Large Cluster Complexes With Almost 500 Silver Atoms Synthesized

Date:
January 11, 2008
Source:
Wiley-Blackwell
Summary:
Scientists have been able to synthesize four new, particularly large and silver-rich clusters, and to determine their crystal structures.

Nanoscopic “lumps” of atoms, known as clusters, are the specialty of a research team headed by Dieter Fenske from the University of Karlsruhe and the Forschungszentrum Karlsruhe. The production and characterization of clusters made of interesting semiconductor materials are a main focus of this group. The team has now been able to synthesize four new, particularly large and silver-rich clusters, and to determine their crystal structures.

Two or three-dimensional nanostructures of semiconductor materials are of interest for future nanoelectronic applications. Such structures could be built of arrays of clusters. A cluster is an accumulation of atoms or molecules that includes hundreds or thousands of atoms. Tiny as they are, to some degree clusters have completely properties to those of “normal sized” (macroscopic) solid particles. This difference is caused by the high surface-to-volume ratio. In order to precisely interpret the measured physical properties of clusters, it is important to understand the atomic structure of these nanoparticles.

One of the things Fenske and his team are working on is the synthesis of metal-rich clusters of the elements sulfur, selenium, and tellurium (the chalcogens). For the metallic component in these systems, the coinage metals copper and silver are well suited. By using specially developed synthetic methods, the scientists were able to make molecular cluster complexes. In this process, cluster cores made of metal and chalcogen atoms are surrounded by a protective shell of organic ligands.

This protective coat prevents the tiny lumps from aggregating into larger particles or solids. This trick made it possible for the researchers to make particularly large silver-rich clusters. The newest members of this family of clusters consist of distorted spherical silver-chalcogenide cores with diameters between two and four nanometers. Their surfaces are protected with thiolate or phosphane ligands.

Characterizing the structures of such large metal-rich cluster complexes by X-ray crystallographic studies is extremely difficult. It is actually impossible to determine the exact composition. Defects in the crystal lattice are one reason. The tendency to have defects increases as the number of silver atoms grows. However, by using a combination of X-ray diffraction, mass spectrometry, and electron microscopy, the researchers did succeed in deriving idealized empirical formulas and idealized atomic structures for their clusters. The most silver-rich compound consists of clusters with approximately 490 silver and 188 sulfur atoms, as well as 114 sulfur-organic ligands, and an idealized composition [Ag490S188(StC5H11)114].

The article Synthesis and Crystal Structures of the Ligand-Stabilized Silver Chalcogenide Clusters [Ag154Se77(dppxy)18], [Ag320(StBu)60S130(dppp)12], [Ag352S128(StC5H11)96] and [Ag490S188(StC5H11)114 was published in Angewandte Chemie International Edition, doi: 10.1002/anie.200704249


Story Source:

The above story is based on materials provided by Wiley-Blackwell. Note: Materials may be edited for content and length.


Cite This Page:

Wiley-Blackwell. "Silver-rich Lumps: Large Cluster Complexes With Almost 500 Silver Atoms Synthesized." ScienceDaily. ScienceDaily, 11 January 2008. <www.sciencedaily.com/releases/2008/01/080109173809.htm>.
Wiley-Blackwell. (2008, January 11). Silver-rich Lumps: Large Cluster Complexes With Almost 500 Silver Atoms Synthesized. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2008/01/080109173809.htm
Wiley-Blackwell. "Silver-rich Lumps: Large Cluster Complexes With Almost 500 Silver Atoms Synthesized." ScienceDaily. www.sciencedaily.com/releases/2008/01/080109173809.htm (accessed October 21, 2014).

Share This



More Matter & Energy News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Gulfstream G500, G600 Unveiling

Gulfstream G500, G600 Unveiling

Flying (Oct. 20, 2014) Watch Gulfstream's public launch of the G500 and G600 at their headquarters in Savannah, Ga., along with a surprise unveiling of the G500, which taxied up under its own power. Video provided by Flying
Powered by NewsLook.com
Japanese Scientists Unveil Floating 3D Projection

Japanese Scientists Unveil Floating 3D Projection

Reuters - Innovations Video Online (Oct. 20, 2014) Scientists in Tokyo have demonstrated what they say is the world's first 3D projection that floats in mid air. A laser that fires a pulse up to a thousand times a second superheats molecules in the air, creating a spark which can be guided to certain points in the air to shape what the human eye perceives as an image. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
What We Know About Microsoft's Rumored Smartwatch

What We Know About Microsoft's Rumored Smartwatch

Newsy (Oct. 20, 2014) Microsoft will reportedly release a smartwatch that works across different mobile platforms, has a two-day battery life and tracks heart rate. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins