Bernd Winter and colleagues, from BESSY, Max-Born-Institut, Uppsala University, and MPI für Dynamik und Selbstorganisation, report in the current issue of Nature (E. F. Aziz et al., Nature, 2008, 455, 89) how water solvates its intrinsic hydroxide (OH-) anion. Unraveling this behavior is important to advance the understanding of aqueous chemistry and biology.
Using a resonance (photo) core-electron spectroscopy technique, with sub ten-femtosecond temporal resolution, and employing synchrotron radiation in conjunction with a liquid microjet, the researchers find that OH- is capable of donating a transient hydrogen bond to a neighboring water molecule. Their experiment thus disproves the classical, so-called proton-hole picture, assuming that OH- is a hydrogen-bond acceptor only.
The weak OH- hydrogen donor bond is responsible for a distinct intensity pattern in the electron spectra, and is connected with a unique energy transfer (intermolecular Coulombic decay) between the oxygen 1s core-excited hydroxide ion and a neighboring water molecule. It is the first time such a process is observed in an aqueous system. To confirm that the measurements exclusively probe the weak OH- hydrogen donor bond at such high sensitivities the team has conducted comparative measurements of halide ions in water.
They find that chloride and isoelectronic fluoride do not exhibit this energy-transfer channel, which corroborates recent structural diffusion models for the unusually migration of the hydroxide ion in water. The work marks a step forward into studying very fast dynamical processes in water and aqueous solutions.
Christine Vollgraf | alfa
Multi-institutional collaboration uncovers how molecular machines assemble
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Fertilized egg cells trigger and monitor loss of sperm’s epigenetic memory
02.12.2016 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
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The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
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Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
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