With a combination of a x-ray free-electron laser and spectroscopy, the team has managed to see the electronic structure of a manganese complex, a chemical compound related to how photosynthesis splits water.
Caption: Ultra-short x-ray pulse striking molecules containing manganese. Illustration: Greg Stewart, National Accelerator Laboratory vid Stanford University
The experiments used the Linac Coherent Light Source (LCLS), which is a free-electron x-ray laser facility at Stanford University in the US. The wavelength of the laser is roughly the same as the breadth of an atom, and each pulse of light lasts 50 femtoseconds (10-15). This is an extremely short interval of time: there are more femtoseconds in one second than there are seconds in a person’s life. Such extremely short wavelengths and short light pulses constitute ideal conditions for imaging chemical reactions with atomic resolution at room temperature while the chemical reactions are ongoing.
The research group has previously used LCLS to perform structural analyses of isolated photosynthesis complexes from plants’ photosystem II at room temperature. Now the group has combined the method with spectroscopy and is the first team to succeed in seeing at LCLS the electronic structure of a manganese complex similar to that found in photosystem II. Manganese is a transitional metal that, together with calcium and oxygen, forms the water-splitting catalyst in photosystem II.
A very simple example of a spectrometer is a prism, which separates sunlight into all the colors of the rainbow. The spectrometer used in this study functions in a similar manner, but with a group of 16 specialized crystals that diffract the x-rays emitted from the sample in resonse of being excited by an x-ray pulse onto a detector array.
To the delight of the scientists, the manganese compounds remained intact long enough for them to observe detailed information about the electronic structure before the compounds were destroyed by the very intense X-ray laser beam.
“Having both structural information and spectroscopic information means that we can much better understand how the structural changes of the whole complex and the chemical changes on the active surface of the catalysts work together to enable the enzymes to perform complex chemical reactions at room temperature,” says Johannes Messinger, professor at the Department of Chemistry at Umeå University.
The chemical reaction the research group aims to understand is the splitting of water in photosystem II, as this understanding is also key for developing artificial photosynthesis– that is, for building devices for producing hydrogen from sunlight and water. To be able to exploit sunlight for producing fuels that can be stored and the used when needed would help solve the world’s ever-more acute energy problems.
The new research findings are being published in the highly regarded journal Proceedings of the National Academy of Sciences, PNAS.
Two major research projects at Umeå University are focusing on the development of artificial photosynthesis by imitating plants’ very successful way of exploiting solar energy. Both projects (“solar fuels” and “artificial leaf”) are directed by Johannes Messinger, professor at the Department of Chemistry at Umeå University.Original publication:
Ingrid Söderbergh | idw
Study shines light on brain cells that coordinate movement
26.06.2017 | University of Washington Health Sciences/UW Medicine
New insight into a central biological dogma on ion transport
26.06.2017 | Aarhus University
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
26.06.2017 | Life Sciences
26.06.2017 | Physics and Astronomy
26.06.2017 | Information Technology