| AVS 60th International Symposium and Exhibition | |
| Ions at Aqueous Interfaces Focus Topic | Monday Sessions |
| Session IA+AI+BI+IS+NL+SS-MoA |
| Session: | Ions at Aqueous Interfaces |
| Presenter: | M. Bonn, Max Planck Institute for Polymer Research, Germany |
| Authors: | M. Bonn, Max Planck Institute for Polymer Research, Germany H.J. Bakker, FOM Institute AMOLF, Netherlands Z. Zhang, Max Planck Institute for Polymer Research, Germany E.H.G. Backus, Max Planck Institute for Polymer Research, Germany L. Piatkowski, FOM Institute AMOLF, Netherlands |
| Correspondent: | Click to Email |
We investigate the vibrational dynamics and energy transfer between interfacial water molecules, in the presence of sodium chloride and sodium iodide salts, using 2-dimensional, femtosecond surface-specific vibrational spectroscopy. We find that both the vibrational lifetime and the intramolecular energy transfer for anion associated interfacial water molecules is slower than for non ion-bound interfacial water molecules. The analysis of the time-dependent slope of the 2-dimensional sum frequency response reveals that the intermolecular resonant energy transfer between the interfacial water molecules is significantly slowed down by the presence of ions. Accordingly, the decay of the frequency-frequency correlation function is slower for NaI than for NaCl solution. This finding provides direct evidence of the higher surface propensity for iodide than for chloride ion, and allows for the quantification of interfacial density of halide ions for both systems.