For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.
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.
To date, it has not been possible to conduct a spectroscopic or electron microscopic analysis of hydrogen and the hydrogen bonds in single molecules, and investigations using atomic force microscopy have also not yielded any clear results.
Dr. Shigeki Kawai, from Professor Ernst Meyer’s team at the Swiss Nanoscience Institute and the Department of Physics at the University of Basel, has now succeeded in using a high-resolution atomic force microscope to study hydrogen atoms in individual cyclic hydrocarbon compounds.
Choosing the right molecules for a clear view
In close collaboration with colleagues from Japan, the researchers selected compounds whose configuration resembles that of a propeller. These propellanes arrange themselves on a surface in such a way that two hydrogen atoms always point upwards. If the tip of the atomic force microscope, which is functionalized with carbon monoxide, is brought close enough to these hydrogen atoms, hydrogen bonds are formed that can then be examined.
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 from the University of Basel’s Swiss Nanoscience Institute network have opened up new ways to identify three-dimensional molecules such as nucleic acids or polymers via observation of hydrogen atoms.
Shigeki Kawai, Tomohiko Nishiuchi, Takuya Kodama, Peter Spijker, Rémy Pawlak, Tobias Meier, John Tracey, Takashi Kubo, Ernst Meyer, Adam S. Foster
Direct quantitative measurement of the C=O···H-C bond by atomic force microscopy
Science Advances (2017), doi: 10.1126/sciadv.1603258
Prof. Dr. Ernst Meyer, University of Basel, Department of Physics, tel. +41 61 207 37 24, email: email@example.com
Reto Caluori | Universität Basel
Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)
Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
17.08.2018 | Physics and Astronomy
17.08.2018 | Information Technology
17.08.2018 | Life Sciences