Pulses from an atom-sharp tip enable researchers to break and form chemical bonds at will.
Chemical reactions often produce messy mixtures of different products. Hence, chemists spend a lot of time coaxing their reactions to be more selective to make particular target molecules. Now, an international team of researchers has achieved that kind of selectivity by delivering voltage pulses to a single molecule through an incredibly sharp tip.
“Controlling the pathway of a chemical reaction, depending on the voltage pulses used, is unprecedented and very alluring to chemists,” says KAUST's Shadi Fatayer.
The team used an instrument that combines scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Both techniques can map out the positions of atoms within individual molecules using a tip that may be just a few atoms wide. But the voltage can also be used to break bonds within a molecule, potentially allowing new bonds to form.
“Tip-controlled reactions have been previously performed, but there was no control over the final product,” Fatayer says. “The selectivity is the key element here — depending on the polarity and value of the voltage pulses, we can form and break different internal bonds at will.”
Read more at KAUST Discovery.
