Abstract
We study the temperature dependence of the orientational mobility of water molecules solvating hydrophobic molecular groups with femtosecond midinfrared spectroscopy. We observe that these dynamics show a strong temperature dependence. At temperatures <30° C the solvating water molecules show a reorientation time >10 ps, which is more than four times slower than in bulk water. With increasing temperature, the reorientation of the solvating molecules strongly accelerates and becomes much more equal to the reorientation rate of the molecules in the bulk liquid. These observations indicate that water molecules form relatively rigid solvation structures around hydrophobic molecular groups that melt at elevated temperatures.
| Original language | English |
|---|---|
| Article number | 214511 |
| Number of pages | 6 |
| Journal | Journal of Chemical Physics |
| Volume | 130 |
| Issue number | 21 |
| DOIs | |
| Publication status | Published - 2009 |
| Externally published | Yes |
Funding
This work was part of the research program of the “Stichting voor Fundamenteel Onderzoek der Materie (FOM),” which is financially supported by the “Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO).” We also acknowledge financial support from the Villum Kann Rasmussen Foundation. We would like to thank Mischa Bonn, Damien Laage, and Casey Hynes for useful discussions.