Researchers from the University of Basel’s Swiss Nanoscience Institute network have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope.
Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are connected to one another via hydrogen atoms, an interaction known as hydrogen bonding.
These interactions play an important role in nature, because they are responsible for specific properties of proteins or nucleic acids and, for example, also ensure that water has a high boiling temperature.
Hydrogen bonds are much weaker than chemical bonds, but stronger than intermolecular van der Waals interactions.
The measured forces and distances between the oxygen atoms at the tip of the atomic force microscope and the propellane’s hydrogen atoms correspond very well to the calculations performed by Prof. Adam S. Foster from Aalto University in Finland.
They show that the interaction clearly involves hydrogen bonds. The measurements mean that the much weaker van der Waals forces and the stronger ionic bonds can be excluded.
With this study, the researchers have opened up new ways to identify three-dimensional molecules such as nucleic acids or polymers via observation of hydrogen atoms.
