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Much of chemistry is about understanding how bonds
are made and broken. For most of the history of chemistry, only single,
double or triple bonds were known. Multiple bonds are particularly
important in carbon chemistry, but only certain metals are
theoretically capable of more than triple bonds, said Philip Power,
professor of chemistry at UC Davis and senior author on the paper.
The dark red crystals were synthesized by Tailuan
(Peter) Nguyen, a graduate student in Power's laboratory. The
chromium-based compound is stable at room temperature but decomposes
in the presence of water, and spontaneously ignites when exposed to
air.
To make the compound, Nguyen and Power attached
large carbon-based molecules to chromium atoms, constraining how they
could behave. They were then able to coax the chromium atoms to bond
with each other. The multiple bonding was confirmed by X-ray
crystallography and magnetic measurements.
As far as we know, no comparable compound exists in
nature, Power said.
In addition to Nguyen and Power, other authors on
the paper were postdoctoral researcher Andrew Sutton, theorist Marcin
Brynda and crystallographer James Fettinger at the UC Davis chemistry
department; and Gary Long, professor of chemistry at the University of
Missouri, Rolla. Peter Klavins and Long Pham at the UC Davis physics
department carried out magnetic measurements for the study.
The work is published online in Science Express and
will appear in the print version of the journal Science later this
year. |
