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
New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg
Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
24.02.2017 | Life Sciences
24.02.2017 | Life Sciences
24.02.2017 | Trade Fair News