Chemists Identify Organic Molecules That Mimic Metals

TECH SPACE

Molecular structure of the cyclic alkyl amino carbene. (Blue - nitrogen; red - carbene carbon; gray - normal carbon.)

by Staff Writers
Riverside, CA (SPX) Apr 23, 2007
A limitation in using hydrogen as a fuel in hydrogen-powered vehicles is the difficulty involved in storing it in a cost-effective and convenient manner. While it is possible to store hydrogen using metals, the resulting products often can be prohibitively expensive and cause environmental problems.

Chemists at UC Riverside now offer a possible solution. A class of carbenes - molecules that have unusual, highly reactive carbon atoms - can mimic, to some extent, the behavior of metals, the chemists have found. Called cyclic alkyl amino carbenes or CAACs, these organic molecules, the researchers report, could be used to develop carbon-based systems for storing hydrogen.

Study results appear in the April 20 issue of Science.

In their experiments, the researchers found that the CAACs can split hydrogen under extremely mild conditions, a behavior that has long been seen in metals reacting with hydrogen.

"The mode of action of these organic molecules, however, is totally different from that of metals," said Guy Bertrand, a distinguished professor of chemistry who led the research. "Moreover, the CAACs are able to split ammonia as well - an extremely difficult task for metals."

Bertrand explained that such a splitting of ammonia, under certain conditions, can pave the way for transforming abundant and inexpensive ammonia into useful amino compounds used to make pharmaceuticals and bulk industrial materials. "This is one of the top challenges for the 21st century," he said.

According to the UCR research team, the metal-mimicking carbenes offer another low-cost and low-toxicity benefit: Scientists now may be able to use non-metallic catalysts for a reaction, called "hydrogenation reaction," which plays a critical role in the food, petrochemical and pharmaceutical industries.

In their study, the researchers exposed a solution of CAACs to both gaseous hydrogen and liquid ammonia. "We used nuclear magnetic resonance spectroscopy to analyze the products," said Guido Frey, the first author of the research paper and a postdoctoral fellow, supported by the Alexander von Humboldt Foundation, in Bertrand's lab. "And we used single crystal X-ray diffraction analysis to confirm the structure of the products."

A carbene is a molecule that has a carbon atom with six electrons instead of the usual eight. Because of the electron deficiency, carbenes are highly reactive and usually unstable in nature.

Email This Article

TECH SPACE

Colombia Launches First Satellite

Bogota, Columbia (Xinhua) Apr 19, 2007
A Russian-Ukrainian rocket put Libertad-1, the first Colombian satellite, into orbit Tuesday, the satellite's designers said.

ENERGY TECH BHP Billiton Responds To Local Newspapers Fact Errors On Cabrillo Port Ethanol Vehicles Pose A Significant Risk To Human Health Japan And US Eye Emission-Free Coal Plant Gazprom Finalizes Deal To Buy Half Stake In Sakhalin 2	CIVIL NUCLEAR Floating NPP Will Be Safer Russian Built Reactor Block 1 Powers Up In China EON To Buy Land In Finland For New Nuclear Plant Fault At Controversial Czech Nuclear Plant
BLUE SKY NASA Aims To Clear Up Mystery Of Elusive Clouds At Edge Of Space University Of Colorado Instruments To Launch On NASA Cloud Mission Powerful New Tool To Track Atmospheric Carbon Dioxide By Source Sun-Warmed Air Pollution Flows East From Asia	WOOD PILE Greater Use Of Biofuels Threatens Rain Forests Soybean Planting Hastens Drying Of Amazonia Study Projects Effects Of Forest Management In Oregon Coast Range China Demand Driving Endangered Tree To Extinction
FARM NEWS Gates Grant To Help Poor Countries Contribute To Doomsday Seed Vault Winter Flounder On The Fast Track To Recovery Satellite Images Aid Implementation Of Agricultural Reforms Farmland Across China At Risk From Pollution	CAR TECH Driverless Car Goes On Show In London Made In USA Losing Cachet Technique Creates Metal Memory And Could Lead To Vanishing Dents Geneva Show Hints At Green Fuel Jumble For Motorists
AEROSPACE Australia Fears Jet Flight Guilt Could Hit Tourism New FAA Oceanic Air Traffic System Designed By Lockheed Martin Fully Operational Nondestructive Testing Keeps Bagram Aircraft Flying NASA Seeks New Research Proposals	NUCLEAR SPACE Could NASA Get To Pluto Faster? Space Expert Says Yes - By Thinking Nuclear NASA plans to send new robot to Jupiter Los Alamos Hopes To Lead New Era Of Nuclear Space Tranportion With Jovian Mission Boeing Selects Leader for Nuclear Space Systems Program

The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement