Proton transfer and the diffusion of H+ and OH- ions along water wires.

Proton transfer and the mobilities of the H+ and OH- ions from studies of a dissociating model for water.

Hydrogen (H(+)) and hydroxide (OH(-)) ions in aqueous solution have anomalously large diffusion coefficients, and the mobility of the H(+) ion is nearly twice that of the OH(-) ion. We describe molecular dynamics simulations of a dissociating model for liquid water based on scaling the interatomic potential for water developed by Ojamäe-Shavitt-Singer from ab initio studies at the MP2 level. We...

H+-type and OH−-type biological protonic semiconductors and complementary devices

Proton conduction is essential in biological systems. Oxidative phosphorylation in mitochondria, proton pumping in bacteriorhodopsin, and uncoupling membrane potentials by the antibiotic Gramicidin are examples. In these systems, H(+) hop along chains of hydrogen bonds between water molecules and hydrophilic residues - proton wires. These wires also support the transport of OH(-) as proton hole...

Note: recombination of H+ and OH- ions along water wires.

The onset of electron-induced proton-transfer in hydrated azabenzene cluster anions.

The prospect that protons from water may be transferred to N-heterocyclic molecules due to the presence of an excess electron is studied in hydrated azabenzene cluster anions using anion photoelectron spectroscopy and computational chemistry. In the case of s-triazine (C3H3N3), which has a positive adiabatic electron affinity, proton transfer is not energetically favored nor observed experiment...

Proton transfer dynamics at the membrane/water interface: dependence on the fixed and mobile pH buffers, on the size and form of membrane particles, and on the interfacial potential barrier.

Crossing the membrane/water interface is an indispensable step in the transmembrane proton transfer. Elsewhere we have shown that the low dielectric permittivity of the surface water gives rise to a potential barrier for ions, so that the surface pH can deviate from that in the bulk water at steady operation of proton pumps. Here we addressed the retardation in the pulsed proton transfer across...