Protons and Hydroxide Ions in Aqueous Systems.
Understanding the structure and dynamics of water's constituent ions, proton and hydroxide, has been a subject of numerous experimental and theoretical studies over the last century. Besides their obvious importance in acid-base chemistry, these ions play an important role in numerous applications ranging from enzyme catalysis to environmental chemistry. Despite a long history of research, many fundamental issues regarding their properties continue to be an active area of research. Here, we provide a review of the experimental and theoretical advances made in the last several decades in understanding the structure, dynamics, and transport of the proton and hydroxide ions in different aqueous environments, ranging from water clusters to the bulk liquid and its interfaces with hydrophobic surfaces. The propensity of these ions to accumulate at hydrophobic surfaces has been a subject of intense debate, and we highlight the open issues and challenges in this area. Biological applications reviewed include proton transport along the hydration layer of various membranes and through channel proteins, problems that are at the core of cellular bioenergetics.
The Fritz Haber Research Center, Institute of Chemistry, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
Noam
N
Agmon
FOM Institute AMOLF , Science Park 104, 1098 XG Amsterdam, The Netherlands.
Huib J
HJ
Bakker
Fritz Haber Institute of the Max Planck Society , Faradayweg 4-6, 14195 Berlin, Germany.
R Kramer
RK
Campen
Manchester Institute of Biotechnology, School of Chemistry, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Richard H
RH
Henchman
Johannes Kepler University Linz , Institute of Biophysics, Gruberstrasse 40, 4020 Linz, Austria.
Peter
P
Pohl
Laboratory for Fundamental BioPhotonics (LBP), Institute of Bioengineering (IBI), and Institute of Material Science (IMX), School of Engineering (STI), and Lausanne Centre for Ultrafast Science (LACUS), École Polytechnique Fédérale de Lausanne (EPFL) , CH-1015, Lausanne, Switzerland.
Sylvie
S
Roke
Fritz Haber Institute of the Max Planck Society , Faradayweg 4-6, 14195 Berlin, Germany.|Department of Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago , Chicago, Illinois 60637, United States.
Martin
M
Thämer
CMSP Section, The Abdus Salaam International Center for Theoretical Physics , I-34151 Trieste, Italy.
Ali
A
Hassanali
D000143:Acids / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D006878:Hydroxides / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D011789:Quantum Theory; D013500:Surface Tension; D014867:Water / Q000737:chemistry*
D000143:Acids; D006878:Hydroxides; D008051:Lipid Bilayers; D008565:Membrane Proteins; D014867:Water; D006859:Hydrogen; C031356:hydroxide ion