3.1 Dynamics of Condensed Phase Molecular Systems

The people involved:
Jakob Schauss, Achintya Kundu, Fabian Dahms, Jia Zhang, Erik T. J. Nibbering, Benjamin Fingerhut, Thomas Elsaesser

National and international collaboration: Ehud Pines,^† Shavkat I. Mamatkulov,^o Florian N. Brünig,* Roland Netz.* Douwe Jan Bonthuis,^+
†: Department of Chemistry, Ben Gurion University of the Negev, Beer-Sheva, 84105 Israel.
^o: Institute of Material Sciences of Uzbekistan Academy of Sciences, Tashkent100084, Uzbekistan.
*: Fachbereich Physik, Freie Universität Berlin, Berlin14195, Germany.
⁺: Institute of Theoretical and Computational Physics, Graz University of Technology, Graz8010, Austria.

Phase 6 (2018-2024):

In the sixth period we aim to tackle with in-depth detail the dynamics and interactions of interfacial water around phosphate groups, as hydrated ions in solution or as key structural units in the sugar-phosphate backbones of DNA and RNA. We further explore the ultrafast dynamics of hydrated protons subject to various solution conditions.

6-1 Ultrafast dynamics of hydrated phosphate-counterion interactions
6-2 Ultrafast dynamics of hydrated excess protons

1. RNA sugar-phosphate backbone vibrations as sensitive probes for hydration shell water molecules.

2. Role of counterions for the structure and dynamics of DNA and RNA polymers.

3. Probing ultrafast dynamics of phosphate-magnesium ion interactions.

4. Main structures proposed for hydrated proton species.

5. Proton transfer mode at 1150 cm^-1 as marker mode of the Zundel cation H₅O₂⁺, prepared in acetonitrile solution.

6. 2D-IR spectroscopy of the proton transfer mode of the Zundel cation H₅O₂⁺ in CH3CN unequivocally demonstrates its potential double well character subject to extremely fast electric field-driven fluctuations and concomittant spectral diffusion and vibrational redistribution.

7. Comparison of 2D-IR spectra of the proton transfer mode of the Zundel cation H₅O₂⁺ in H₂O and in CH₃CN shows the dominant role of the Zundel cation in aqueous solution.