How far can a proton make its presence felt when embedded in water?

Photo: Erik T. J. Nibbering Oxygen K-edge spectra of the water monomer, and of hydrated proton complexes formed by mixing HI and H₂O in 1 : 8 and 1 : 3.5 mixing ratios respectively, showing the distinct difference in the pre-, main and post-edge band features of monomer water molecules, of hydration shell water molecules and of the inner H7O₃⁺ complex.

An international team of researchers has gained important insights into the electronic structure of hydrated proton complexes in solution: The involvement of a certain number of water molecules in the uptake of an excess proton in aqueous environments exhibits a structural hierarchy that is more extensive than is often assumed. This new finding could be important in understanding proton transport in energy conversion in fuel cells or signal transduction in transmembrane proteins.

The work involved research teams from the Max Born Institute, Universität Hamburg – partly from CFEL - and the Cluster of Excellence "CUI: Advanced Imaging of Matter", Stockholm University, Ben Gurion University of the Negev and Uppsala University.

Read the full press release from the Max Born Institute. The results were published electronically in the international edition of Angewandte Chemie.