cad a22 4500 555301133 20190610052253.0 cr unu---uuuuu 190206e20180621xx s 000 0 eng 10.5167/uzh-161668 doi 10.1063/1.5034225 doi (ZORA)oai:www.zora.uzh.ch:161668 540 ddc Aqueous solvation from the water perspective [Elektronische Daten] [Saima Ahmed, Andrea Pasti, Ricardo J Fernández-Terán, Gustavo Ciardi, Andrey Shalit, Peter Hamm] openAccess eu-repo The response of water re-solvating a charge-transfer dye (deprotonated Coumarin 343) after photoexcitation has been measured by means of transient THz spectroscopy. Two steps of increasing THz absorption are observed, a first similar to 10 ps step on the time scale of Debye relaxation of bulk water and a much slower step on a 3.9 ns time scale, the latter of which reflecting heating of the bulk solution upon electronic relaxation of the dye molecules from the S-1 back into the S-0 state. As an additional reference experiment, the hydroxyl vibration of water has been excited directly by a short IR pulse, establishing that the THz signal measures an elevated temperature within similar to 1 ps. This result shows that the first step upon dye excitation (10 ps) is not limited by the response time of the THz signal; it rather reflects the reorientation of water molecules in the solvation layer. The apparent discrepancy between the relatively slow reorientation time and the general notion that water is among the fastest solvents with a solvation time in the sub-picosecond regime is discussed. Furthermore, non-equilibrium molecular dynamics simulations have been performed, revealing a close-to-quantitative agreement with experiment, which allows one to disentangle the contribution of heating to the overall THz response from that of water orientation. Published by AIP Publishing. Department of Chemistry zora Physical and Theoretical Chemistry, General Physics and Astronomy zora Ahmed Saima joint author Pasti Andrea joint author Fernández-Terán Ricardo J. joint author Ciardi Gustavo joint author Shalit Andrey joint author Hamm Peter joint author Journal of Chemical Physics 148(23):234505 https://www.zora.uzh.ch/id/eprint/161668/1/1.5034225.pdf text/html WWW-Backlink auf das Repository 1 Journal Article PeerReviewed zora unknown/Swiss National Science Foundation (SNF) through the NCCR MUST/200021_165789/1 zora grantAgreement ZORA 856 40 https://www.zora.uzh.ch/id/eprint/161668/1/1.5034225.pdf text/html WWW-Backlink auf das Repository ZORA 700 1- Ahmed Saima joint author ZORA 700 1- Pasti Andrea joint author ZORA 700 1- Fernández-Terán Ricardo J. joint author ZORA 700 1- Ciardi Gustavo joint author ZORA 700 1- Shalit Andrey joint author ZORA 700 1- Hamm Peter joint author ZORA 773 0- Journal of Chemical Physics 148(23):234505 BK010053 XK010053 XK010000 ZORA ZORA ZORA Journal Article openAccess