Influence of protons on water molecules

How hydrogen ions or protons interact with their aqueous environment has great practical relevance, whether in fuel cell technology or in the life sciences. Now, a large international consortium at the X-ray source BESSY II has investigated this question experimentally in detail and discovered new phenomena. For example, the presence of a proton changes the electronic structure of the three innermost water molecules, but also has an effect via a long-range field on a hydrate shell of five other water molecules.

Excess protons in water are complex quantum objects with strong interactions with the dynamic hydrogen bond network of the liquid. These interactions are surprisingly difficult to study. Yet so-called proton hydration plays a central role in energy transport in hydrogen fuel cells and in signal transduction in transmembrane proteins. While the geometries and stoichiometries have been extensively studied both in experiments and in theory, the electronic structure of these specific hydrated proton complexes remains a mystery.

A large collaboration of groups from the Max Born Institute, the University of Hamburg, Stockholm University, Ben Gurion University and Uppsala University has now gained new insights into the electronic structure of hydrated proton complexes in solution.

Using the novel flatjet technology, they performed X-ray spectroscopic measurements at BESSY II and combined them with infrared spectral analysis and calculations. This allowed them to distinguish between two main effects: Local orbital interactions determine the covalent bond between the proton and neighbouring water molecules, while orbital energy shifts measure the strength of the proton’s extended electric field.

Read more on the HZB website

Image: The spectral fingerprints of water molecules could be studied at BESSY II. The result: the electronic structure of the three innermost water molecules in an H7O3+ complex is drastically changed by the proton. In addition, the first hydrate shell of five other water molecules around this inner complex also changes, which the proton perceives via its long-range electric field.

Credit: © MBI

A welcoming and friendly community awaits!

Challenges are part of daily life at a synchrotron. In his #LightSourceSelfie, Tomasz talks about the importance of flexibility and how teams work together, adjusting to overcome challenges and get things done. When describing the synchrotron community, Tomasz says, “I think it is one of the most welcoming and friendly communities I have ever met.” Tomasz is driven by curiosity and the need to help others. He says, “Light sources are a nice combination of both because I can actually help people to solve their problems, their interesting scientific problems, and this gives me the everyday fulfilment.”

After over a decade working in infrared spectroscopy, Tomasz is excited that SOLARIS now has funding to construct an infrared beamline that will allow scientists to do cutting edge infrared imaging experiments of cells and tissues primarily for cancer diagnostics and understanding of biological systems.

To find out more about SOLARIS, visit

Metal pollutants cause metabolic alterations in algae

Contamination by metals like cadmium or mercury is considered a serious threat to the environment and human health. Several human activities such as mining, metallurgy industry, and extensive use of mineral fertilizers are the main sources of ongoing metal pollution in numerous ecosystems. This environmental risk is potentiated by bioaccumulation and trophic chain biomagnification phenomena, which are associated with the long persistence of toxic metals in the polluted ecosystems. Aquatic and soil ecosystems affected by runoffs loaded with toxic metals are particularly vulnerable, where primary producers photosynthetic organisms (phytoplankton and soil microalgae) represent the first stage of pollution build-up. Knowledge about mechanisms of toxicity in these organisms is essential for appropriate assessment of environmental risks.

Researchers from the Plant Physiology Laboratory of the Department of Biology, also affiliated with the Research Centre for Biodiversity and Global Change, at the Autonomous University of Madrid (UAM), have discovered the major changes of biomolecules caused by cadmium and mercury in the model green microalga Chlamydomonas reinhardtii.

The use of synchrotron technology at MIRAS beamline was a valuable tool and has made it possible to analyze in detail variations in the biomolecular pattern caused by heavy metals at levels of resolution rarely described before. “Among the cellular components that readily changed upon metal treatments, we detected alterations in the lipid composition by synchrotron light infrared spectroscopy at ALBA, which corresponded to accumulation of neutral lipids and increased fatty unsaturation” specifies Ángel Barón, scientist at UAM.

Read more on the ALBA website

Image: Electron transmission microscopy of Chlamydomonas reinhardtii cells to show alterations caused by cadmium and mercury. The pyrenoid (p) looks aberrant, with proliferation of lipid vesicles (green arrowhead) and starch grains (s). Metals also triggered the appearance of autophagy vesicles (red arrowhead). Right: image of Chlamydomonas reinhardtii 

Credit: image of Chlamydomonas reinhardtii  Wikimedia Commons.