A team of scientists has broken and reapplied a chemical bond in a controlled manner for the first time, it has been reported.

Researchers at Surface Chemistry Laboratory in Wako, Japan, first located the methylaminocarbyne (CNHCH₃) molecule, which was affixed to a platinum surface, according to a report in New Scientist magazine.

The team then removed a single hydrogen atom using a scanning tunnelling microscope (STM) as a cutting tool which applied voltage and broke the bond between the molecule's nitrogen and hydrogen atom, leaving a molecule of methylisocyanide (CNCH₃).

To reattach the hydrogen atom, the team applied hydrogen gas, which caused the platinum surface to catalyse the splitting of the hydrogen molecules into their hydrogen atoms.

These in turn reacted with nitrogen contained in the methylisocyanide molecule to re-form methylaminocarbyne.

This kind of a reversible alteration could potentially be employed in molecular electronics, according to Yousoo Kim who helped conduct the experiments.

Previous attempts at the breaking and restoring chemical bonds for a single atom with an STM have tended to result either in the other bonds being broken or had caused a shift in chemical composition that could feasibly not be reversed.

Source:

Molecular surgery snips off a single atom, 29/06/07
http://www.newscientist.com/article/dn12161

Reversible Control of Hydrogenation of a Single Molecule, 29/06/07
http://www.sciencemag.org/cgi/content/short/316/5833/1883

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