Hydrogen bonds: Scientists find new mechanism

Sep 09, 2008

Water’s unrivaled omnipresence and the crucial role it plays in life drives scientists’ to understand every detail of its unusual underlying properties on the microscopic scale.

Bernd Winter and colleagues, from BESSY, Max-Born-Institut, Uppsala University, and MPI für Dynamik und Selbstorganisation, report in the current issue of Nature 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.

Citation: E. F. Aziz et al., Nature 455, 89 - 91 (04 Sep 2008), doi: 10.1038/nature07252

Source: Max-Born-Institut

Explore further: New insights found in black hole collisions

add to favorites email to friend print save as pdf

Related Stories

Team advances fuel cell car technology

Jan 29, 2015

Dr. Yossef Elabd, professor in the Artie McFerrin Department of Chemical Engineering at Texas A&M University, has developed two fuel cell vehicle platforms for both present day enhancements and future innovation.

Recommended for you

New insights found in black hole collisions

Mar 27, 2015

New research provides revelations about the most energetic event in the universe—the merging of two spinning, orbiting black holes into a much larger black hole.

X-rays probe LHC for cause of short circuit

Mar 27, 2015

The LHC has now transitioned from powering tests to the machine checkout phase. This phase involves the full-scale tests of all systems in preparation for beam. Early last Saturday morning, during the ramp-down, ...

Swimming algae offer insights into living fluid dynamics

Mar 27, 2015

None of us would be alive if sperm cells didn't know how to swim, or if the cilia in our lungs couldn't prevent fluid buildup. But we know very little about the dynamics of so-called "living fluids," those ...

Fluctuation X-ray scattering

Mar 26, 2015

In biology, materials science and the energy sciences, structural information provides important insights into the understanding of matter. The link between a structure and its properties can suggest new ...

Hydrodynamics approaches to granular matter

Mar 26, 2015

Sand, rocks, grains, salt or sugar are what physicists call granular media. A better understanding of granular media is important - particularly when mixed with water and air, as it forms the foundations of houses and off-shore ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.