The vibrating hydroxide ion in water

Multi-Scale Modelling of Water and Hydroxide in Solids and Solutions

“…A snapshot from the ab initio MD simulation is given in Figure 7b and illustrates the strong hydrogen-bonds donated to the hydroxide's O atom, and the much loser and cage-like water structure around the hydroxide's H atom, as discussed in Ref. [13]. The eperimentally measured gas-to-solution frequency shift is seen to be well reproduced by our calculations.…”

“…The effect is illustrated in Figure 8 for the ideal cases of a water molecule and a hydroxide ion (separately) exposed to a uniform electric field [14]. We conclude that the study in [13] both demonstrated that the calculations were able to reproduce the experimentelly determined gas-to-liquid frequency shift (and actually here also the absolute values), and provided an explanation for the observed -positive and modest -frequency shift observed for the hydroxide ion, which is contrary to our experience from the behavior of water molecules.…”

“…The explanation was given in Ref. [13] and confirms that the hydroxide ion in water conforms with the behavior that we had earlier found in the gas-phase [14]: when the ion is exposed to a small electric field (from an ex-ternal source, e.g. its surrounding molecules) the frequency is up-shifted (opposite to what happens for the water molecule), reaches a maximum as the field is increased and then decreases and, for very large electric fields, gives a large downshift compared to the gas-phase OH -frequency.…”

Low Bending Vibrations of Crystalline Water Molecules: An Ongoing Quest or a Final Word – Topical Review – A Tribute to Academician Bojan Šoptrajanov

“…For example, the involvement of an O-H(D) oscillator in an intra-or intermolecular hydrogen bond has been often judged by the direction of the shift in the O-H(D) stretching frequency. The magnitude of this shift, on the other hand, has often been found to be proportional to the interaction strength [10][11][12][13][14][15][16][17]20]. Besides the effect of noncovalent interactions on the static and dynamical properties of the intramolecular O-H(D) oscillators, also the influence of incrystal (or external) electrostatic fields on the statics and dynamics of the O-H(D) oscillators has been thoroughly addressed [21][22][23][24].…”

“…The dynamics of hydrogen bond forming and breaking within liquid water is a subject of continual research interests. Behavior of the essential products of water autoprotolysis process, the H 3 O + and OH -ionic species, has also been a subject of continuing debates in the literature [10][11][12][13][14][15][16][17]. Even very essential issues, such as the ability of the OH -ions to act as hydrogenbond proton donors in bulk water, have been addressed from various viewpoints [10][11][12][13][14][15][16][17].…”