Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Highly Reactive Gold Carbene Complex Shines in Emerald Green

09.07.2014

Heidelberg chemists succeed in isolating carbon-gold compound of “amazing stability”

With a chemical “trick”, scientists at Heidelberg University have succeeded in isolating a stable gold carbene complex. Chemist Prof. Dr. Bernd F. Straub and his team are the first to have created the basis for directly examining the otherwise unstable gold-carbon double bond. Prof. Straub explains that highly reactive gold carbene molecules play an important role in landmark catalysing processes taking place at high speed. The research findings have been published in the German and the international edition of „Angewandte Chemie“, a journal on applied and fundamental chemistry.


The Au=C double bond in the gold carbene compound is the bond between the large golden atom in the middle and the slightly greenish atom below. The position of the atoms was derived from an x-ray crystal structure analysis.

Copyright: Matthias Hussong and Bernd F. Straub, Heidelberg University

Chemical reactions can be accelerated with the aid of catalysts; consequently materials and pharmaceuticals can be manufactured from the raw materials of nature. The study of gold compounds in catalytic processes has proved particularly intensive and successful, according to Prof. Straub. “In numerous scientific studies in the last ten years, experts have been proposing gold carbenes as essential short-lived intermediates in catalytic reactions,” the Heidelberg researcher explains. However, with their high reactivity they escape detailed study: hardly has a gold carbene fragment consisting of the elements gold and carbon emerged – Au for aurum and C for carbon – when it continues to react.

In order to first create a stable complex and isolate a gold carbene structure for research, the two elements were “lured into a cage like a hungry tiger with a bait,” says Matthias Hussong, who is working on his doctoral dissertation in Prof. Straub’s team. The researchers first shielded the gold and carbon from its environment by surrounding them with low-reactive, space-filling chemical groups. Then the two elements were bonded in a carefully planned step – and so the Au=C fragment was “caught” in the gold carbene complex.

... more about:
»Complex »Green »carbene »materials »processes »reactions

The chemists were able to impart “an amazing stability” to the gold carbene, says Prof. Straub – and at the same time to make it literally visible. “Almost all gold complexes are colourless, while the ‘stable’ gold carbene is emerald green,” states the scientist, who heads a research group at Heidelberg University‘s Institute of Organic Chemistry. Further Heidelberg studies showed that gold in its compounds is more than a “soft proton”, as the chemical behaviour of gold had been described to date.

If the gold fragment is replaced by a “real” proton, e.g. the nucleus of hydrogen, the lightest element, this analogous protonated carbene displays a reddish purple colour. “The gold in the gold carbene complex behaves differently from a proton – that is very clear to the eye,” states Prof. Straub. He and his team are now continuing to explore the understanding of gold catalysis, with the aim of using these findings to make catalytic processes more efficient.

Original publications:
Hussong, M. W., Rominger, F., Krämer, P. und Straub, B. F.: Isolierung eines nicht-Heteroatom-stabilisierten Goldcarbens. Angew. Chem. (online veröffentlicht am 20. Juni 2014), doi: 10.1002/ange.201404032
Hussong, M. W., Rominger, F., Krämer, P. and Straub, B. F.: Isolation of a Non-Heteroatom-Stabilized Gold–Carbene Complex. Angew. Chem. Int. Ed. (published online 20 June 2014), doi: 10.1002/anie.201404032

Internet information:
http://www.uni-heidelberg.de/fakultaeten/chemgeo/oci/akstraub/index.html

 
Contact:
Prof. Dr. Bernd F. Straub
Institute of Organic Chemistry
Phone: +49 6221 54-6239
straub@oci.uni-heidelberg.de

Communications and Marketing
Press Office, phone: +49 6221 54-2311
presse@rektorat.uni-heidelberg.de

Marietta Fuhrmann-Koch | idw - Informationsdienst Wissenschaft

Further reports about: Complex Green carbene materials processes reactions

More articles from Life Sciences:

nachricht MACC1 Gene Is an Independent Prognostic Biomarker for Survival in Klatskin Tumor Patients
31.08.2015 | Max-Delbrück-Centrum für Molekulare Medizin in der Helmholtz-Gemeinschaft

nachricht Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Increasingly severe disturbances weaken world's temperate forests

Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.

"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Production research by Fraunhofer IAO honored with three awards at the ICPR 2015

31.08.2015 | Awards Funding

Single-Crystal Phosphors Suitable for Ultra-Bright, High-Power White Light Sources

31.08.2015 | Materials Sciences

Manchester Team Reveal New, Stable 2D Materials

31.08.2015 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>