BERKELEY, CA -- The elusive goal of harnessing the vast potential of one of the earth's most plentiful materials is another step closer to realization. Using ultrafast spectroscopic techniques that provide "stop-action" images within a trillionth of a second, scientists at the U.S. Deparment of Energy's Lawrence Berkeley National Laboratory have obtained the first detailed picture of an alkane-activation reaction at room temperature.
Alkanes are compounds of carbon and hydrogen atoms held together by single bonds. The simplest and most abundant is methane, the primary constituent of natural gas. Chemists have long coveted the use of alkanes as environmentally benign feedstock for clean-burning fuels and a host of petrochemicals, including plastics, solvents, synthetic fibers, and pharmaceutical drugs. The problem has been that the bonds between an alkane's carbon and hydrogen atoms are strong enough to render alkanes generally unreactive.
In the early 1980s, Robert Bergman, a chemist in Berkeley Lab's Chemical Sciences Division (CSD) and with the University of California at Berkeley, led the discovery of a group of organometallic complexes --compounds of metal atoms, such as iridium or rhodium, sandwiched between organic molecules with a unique property. Upon irradiation with ultraviolet light, these organometallics were shown to generate a reaction that is able to break the carbon-hydrogen bonds in alkanes and insert metal atoms into the mix, creating new, much more reactive carbon-metal-hydrogen compounds.
Since discovering this alkane-activating reaction, Bergman has been working
to better understand it with the ultimate aim of designing a catalytic process
that could be used in commercial operations. An obstacle has been that the
reaction takes place within 230 nanoseconds (billionths of a second). To slow
it down for detailed study, Bergman and Bradley Moore, another chemist who also
holds a joint Berkeley Lab-UC Berkeley ap
Contact: Lynn Yarris
DOE/Lawrence Berkeley National Laboratory