Temperature-dependent chemical shift in the aqueous solution of xenon
Peuravaara, Petri (2017-05-19)
Peuravaara, Petri
P. Peuravaara
19.05.2017
© 2017 Petri Peuravaara. Tämä Kohde on tekijänoikeuden ja/tai lähioikeuksien suojaama. Voit käyttää Kohdetta käyttöösi sovellettavan tekijänoikeutta ja lähioikeuksia koskevan lainsäädännön sallimilla tavoilla. Muunlaista käyttöä varten tarvitset oikeudenhaltijoiden luvan.
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:oulu-201705232035
https://urn.fi/URN:NBN:fi:oulu-201705232035
Tiivistelmä
At standard pressure, the chemical shift of Xe-129 in an aqueous solution of xenon exhibits a maximum as a function of temperature at 311 K, which is in contrast to the well-known density maximum of water at 277 K. In the present work, this phenomenon is studied by means of a molecular dynamics simulation, where the xenon chemical shift is computed quantum-chemically for snapshots of the simulation trajectory. Also, a simple semianalytical model is developed in which the water around the xenon atom is interpreted to form a shell of uniform density. Both approaches are found to be able to qualitatively reproduce the maximum. In addition, the chemical shift in the semianalytical model is seen to result as a product of the local water density around the xenon and a term corresponding to the xenon-water collision energetics. The latter term can be seen to shift the location of the maximum up in temperature, as compared to the temperature of maximum density.
Kokoelmat
- Avoin saatavuus [29905]