Scientists at the University of Basel and the Center of Free-Electron Laser Science in Hamburg were able for the first time to successfully sort out single forms of molecules with electric fields and have them react specifically.
Analysis of the reaction rates showed a relation between the spatial structure of the sorted molecules and their chemical reactivity. The results have been published in the renowned magazine «Science».
The reactivity of a chemical compound, that is the rate at which a substance undergoes a chemical reaction, is strongly influenced by the shape of its molecules. Complex molecules often exhibit different shapes, so-called conformers, in which parts of the molecules vary in their spatial arrangement. However, conformers often interconvert between each other under ambient conditions, so that a detailed study of their individual reactivities has been difficult so far.
Scientists around Prof. Stefan Willitsch from the Department of Chemistry at the University of Basel and Prof. Jochen Küpper from the Center for Free-Electron Laser Science in Hamburg (CFEL, DESY) have developed a new experimental setup that allows to study the reactivity of single isolated conformers. The scientists produced a beam of molecules from which they were able to pick specific conformers with a «molecular sorting machine» in order to specifically inject them into a chemical reaction.
The scientists made use of the fact that a change in the shape of a molecule usually also leads to the modification of its dipole moment. The dipole moment describes how a molecule reacts to an external electric field. Inside this sorting machine, a non-uniform electric field deflects single conformers to varying extents so that they are spatially separated.
In a first experiment, the scientists separated two conformers 3-aminophenol, a well-known compound that is widely used in industry. The two conformers only differ in the position of a single hydrogen atom. The separated conformers were then directed into a reaction chamber where they reacted with electrically charged calcium atoms, so-called ions, in a trap. The ions were cooled down with laser light to almost the absolute zero point of temperature scale at minus 273 degrees Celsius. In this way the ions were localized in space and formed an ideal target for reactions with the spatially separated conformers. Thus, the scientists were able to show that one of the conformers reacted twice as fast with the calcium ions than the other, a phenomenon that could be explained by the different electrical properties of the conformers.
The new method allows insight into fundamental reaction mechanisms and the relations between molecular conformation and chemical reactivity, with potentially far-reaching applications in chemical catalysis and the synthesis of new molecules.
Yuan-Pin Chang, Karol D³ugo³êcki, Jochen Küpper, Daniel Rösch, Dieter Wild, Stefan Willitsch
Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions
Science (2013) | doi: 10.1126/science.1242271
• Prof. Dr. Stefan Willitsch, University of Basel, Department of Chemistry, Klingelbergstrasse 80, 4056 Basel, Tel. +41 61 267 38 30, E-Mail: email@example.com
• Prof. Jochen Küpper, Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Tel. +49 40 8998-6330, E-Mail: firstname.lastname@example.org
More articles from Life Sciences:
New genetic research finds shark, human proteins stunningly similar
06.12.2013 | Cornell University
Prostate cancer biomarker may predict patient outcomes
06.12.2013 | Vanderbilt University Medical Center
International team of scientists develops new feedback method for optimizing the laser pulse shapes used in the control of chemical reactions
In many ways, traditional chemical synthesis is similar to cooking. To alter the final product, you can change the ingredients or their ratio, change the method of mixing ingredients, or change the temperature or pressure of the environment of the ingredients.
Like an accomplished chef, chemists have become very skilled ...
A genetic defect protects mice from infection with influenza viruses
A new study published in the scientific journal PLOS Pathogens points out that mice lacking a protein called Tmprss2 are no longer affected by certain flu viruses.
The discovery was made by researchers from the Helmholtz Centre for Infection Research (HZI) in Braunschweig in collaboration with colleagues from Göttingen and ...
The Light: Global study gets underway with online user survey
Light has a fundamental impact on our sense of well-being and performance. In cooperation with Zumtobel, a supplier of lighting solutions, Fraunhofer IAO has launched a global user survey of lighting quality in offices. The objective is to identify the best lighting conditions for a variety of spaces and lighting ...
Quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as “spooky action at a distance,” could be even spookier than Einstein perceived.
Physicists at the University of Washington and Stony Brook University in New York believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.
But here’s the catch: One couldn’t actually ...
A star is formed when a large cloud of gas and dust condenses and eventually becomes so dense that it collapses into a ball of gas, where the pressure heats the matter, creating a glowing gas ball – a star is born.
New research from the Niels Bohr Institute, among others, shows that a young, newly formed star in the Milky Way had such an explosive growth, that it was initially about 100 times brighter than it is now. The results are published in the scientific journal, Astrophysical Journal Letters.
The young ...
06.12.2013 | Materials Sciences
06.12.2013 | Life Sciences
06.12.2013 | Life Sciences
05.12.2013 | Event News
04.12.2013 | Event News
12.11.2013 | Event News