Skoltech scientists said the formula for water
Russian scientists in cooperation with German colleagues have found that the water contains large amounts of short-lived ions. This radically changes the understanding of the dynamic water structure and approaches to the assessment of acidity. The study is published in the journal Scientific Reports.
Natural water is a composition of a mixture of isotopologues —combinations of different isotopes of oxygen and hydrogen, the two elements that make up water.
Scientists from Skoltech and at the University of Stuttgart studied the ion-molecular composition of three isotopologues water — regular (H2O) and heavy (D2O) and light heavyweight (HDO) and found that very short, subpicosecond time intervals of pure liquid water contains large concentrations of short-lived ions H3O and OH — are much higher than considered in the estimation of pH. Up to a few percent of the molecules of H2O have been temporarily ionized.
Ion liquid water play an important role in redox processes, catalytic reactions and electrochemical systems. Previously it was assumed that subamarine tunneling of hydrogen atoms between the molecules H2O, caused by nuclear quantum effects can lead to short-term excess proton States, but to date there has been no experimental confirmation of such conditions, no information on the concentration of excess protons in pure water.
"We used different isotopolog water to identify excess proton condition — presented in a press release quotes one of the study's authors Verdana henni (Henni Ouerdane), Professor of the Center for energy science and technology Skoltech (CEST). — Gradually replacing the hydrogen atoms (H), deuterium (D), we changed the relative particle concentration associated with an excess of protons, such as HD2O , DH2O , H3O-and D3O , and determined their contribution to the cumulative infrared absorption."
In the infrared spectra, the authors saw the highs that existing models could not explain.
"We found concentration-dependent spectral features close to the molecular bending modes of semi-heavy water spectra. We believe that these features are associated with an excess of protons that exist in the picosecond time scale," says Werden.
"While previous studies of water structure was based on the crystallographic experiments and did not reflect water dynamics, our study provides new insight about the complex structure of water in ultra-short time scale," notes lead author, senior researcher at CEST Vasily Artemov.
Scientists believe that the inclusion of ion particles in ultrashort time scale will improve and greatly simplify models of physical-chemical and electrochemical systems in which liquid water plays an important role, and will also help in future studies of anomalous properties of water, for example, in its interaction with the electric field.