New molecules created by UC Riverside chemists have wide applications

October 22, 2009

RIVERSIDE, Calif. - Researchers at the University of California, Riverside have successfully created in the laboratory a class of carbenes, highly reactive molecules, used to make catalysts - substances that facilitate chemical reactions. Until now, chemists believed these carbenes, called "abnormal N-heterocyclic carbenes" or aNHCs, were impossible to make.

Carbenes are made up of unusual carbon atoms and are usually unstable in nature. They attach themselves to metals to form metal-carbene complexes that serve as efficient catalysts used widely in the pharmaceutical industry.

The metal-carbene complexes are formed in two ways: (a) the complex is created in one step, without first preparing carbene independently, and (b) a metal and an independent carbene are brought together to make the complex.

Most often the metal used in a metal-carbene complex is rhodium, gold, platinum or palladium - all of which are very expensive and, in some cases, even toxic. To bring down the cost of catalysts, when possible, carbenes are used independently (without metals) in many chemical reactions.

Until now, aNHCs have been used as only metal-carbene complexes, never independently. Chemists had assumed that aNHCs cannot exist freely, which made them impossible to make.

Now UC Riverside's Guy Bertrand, a distinguished professor of chemistry, and colleagues have challenged that assumption by successfully creating aNHCs that are metal-free and can be used to make any desired complex.

"Many chemical species are believed to be unstable because they do not obey the rules we learned at school, and consequently nobody tries to make them," said Bertrand, who led the research project. "The role of scientists, however, is to challenge former hypotheses. That is just what we did in the case of the aNHCs, and we were successful.

"The aNHCs are stable at room temperature both in the solid state and in solution, which means their application as metal-free catalysts is extremely wide, greatly benefiting industry by making possible scores of new chemical reactions."

Results of the study appear in the Oct. 23 issue of Science.

"This study, reporting the synthesis and characterization of an entirely different class of metal-free NHCs, could open new horizons and have a huge impact on the field of catalysis," said John Schwab, who oversees organic synthesis grants at the National Institutes of Health's National Institute of General Medical Sciences. "The potential applications to drug discovery and manufacture are exciting, since catalytic processes can help keep costs in check and be environmentally friendly, to boot."

Bertrand is interested in making aNHCs commercially available. "We hope many chemists in the world will use these carbenes and find some new applications," he said.

The UCR Office of Technology Commercialization has filed a patent application on the technology and is currently seeking partners in industry interested in developing the technology commercially.

An internationally renowned scientist, Bertrand came to UCR in 2001 from France's national research agency, the Centre National de la Recherche Scientifique (CNRS). He is the director of the UCR-CNRS Joint Research Chemistry Laboratory.

A recipient of numerous awards and honors, most recently he won the 2009-2010 Sir Ronald Nyholm Prize for his seminal research on the chemistry of phosphorus-phosphorus bonds and the chemistry of stable carbenes and their complexes.

He is a recipient of the Japanese Society for Promotion of Science Award, the French-German Humboldt Award, and the International Council on Main Group Chemistry Award. He is a fellow of the American Association for the Advancement of Sciences, and a member of the French Academy of Sciences, the European Academy of Sciences, Academia Europea, and Academies des Technologies.

He has authored more than 300 scholarly papers and holds 35 patents.

Bertrand was joined in the research by Eugenia Aldeco-Perez, Amos J. Rosenthal, and Bruno Donnadieu of UCR; and Gernot Frenking and Pattiyil Parameswaran of Phillips-Universitat Marburg, Germany.
-end-
The research project was funded by the National Institutes of Health. The National Council for Science and Technology (CONACYT), Mexico, provided Aldeco-Perez, the first author of the research paper, with financial support.

The University of California, Riverside (www.ucr.edu) is a doctoral research university, a living laboratory for groundbreaking exploration of issues critical to Inland Southern California, the state and communities around the world. Reflecting California's diverse culture, UCR's enrollment of about 18,000 is expected to grow to 21,000 students by 2020. The campus is planning a medical school and has reached the heart of the Coachella Valley by way of the UCR Palm Desert Graduate Center. The campus has an annual statewide economic impact of more than $1 billion.

A broadcast studio with fiber cable to the AT&T Hollywood hub is available for live or taped interviews. To learn more, call (951) UCR-NEWS.


University of California - Riverside

Related Chemical Reactions Articles from Brightsurf:

Shedding light on how urban grime affects chemical reactions in cities
Many city surfaces are coated with a layer of soot, pollutants, metals, organic compounds and other molecules known as ''urban grime.'' Chemical reactions that occur in this complex milieu can affect air and water quality.

Seeing chemical reactions with music
Audible sound enables chemical coloring and the coexistence of different chemical reactions in a solution.

Nanocatalysts that remotely control chemical reactions inside living cells
POSTECH professor In Su Lee's research team develops a magnetic field-induced heating 'hollow nanoreactors'.

New NMR method enables monitoring of chemical reactions in metal containers
Scientists have developed a new method of observing chemical reactions in metal containers.

Levitating droplets allow scientists to perform 'touchless' chemical reactions
Levitation has long been a staple of magic tricks and movies.

Predicting unpredictable reactions
New research from the University of Pittsburgh's Swanson School of Engineering, in collaboration with the Laboratory of Catalysis and Catalytic Processes (Department of Energy) at Politecnico di Milano in Milan, Italy, advances the field of computational catalysis by paving the way for the simulation of realistic catalysts under reaction conditions.

First-time direct proof of chemical reactions in particulates
Researchers at the Paul Scherrer Institute PSI have developed a new method to analyse particulate matter more precisely than ever before.

Finding the source of chemical reactions
In a collaborative project with MIT and other universities, scientists at Argonne National Laboratory have experimentally detected the fleeting transition state that occurs at the origin of a chemical reaction.

Accelerating chemical reactions without direct contact with a catalyst
Northwestern University researchers demonstrate a chemical reaction produced through an intermediary created by a separate chemical reaction, findings that could impact environmental remediation and fuel production.

Visualizing chemical reactions, e.g. from H2 and CO2 to synthetic natural gas
Scientists at EPFL have designed a reactor that can use IR thermography to visualize dynamic surface reactions and correlate it with other rapid gas analysis methods to obtain a holistic understanding of the reaction in rapidly changing conditions.

Read More: Chemical Reactions News and Chemical Reactions Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.