%0 Journal Article %1 D0NJ02391D %A Schmitt, Hans-Christian %A Fischer, Ingo %A Ji, Lei %A Merz, Julia %A Marder, Todd B. %A Hoche, Joscha %A Röhr, Merle I. S. %A Mitric, Roland %D 2020 %I The Royal Society of Chemistry %J New J. Chem. %K ag_pub1 %P - %R 10.1039/D0NJ02391D %T Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study %U http://dx.doi.org/10.1039/D0NJ02391D %X We investigated isolated 2-hydroxypyrene and its dimer in the gas phase by time- and frequency-resolved photoionisation with picosecond time-resolution. The experiments are supported by simulations that include an extensive conformational search based on the machine learning ANI-1ccx neural network potential combined with automatic structure classification using a data clustering algorithm. Vibrationally resolved spectra of the S1 ← S0 and S2 ← S0 transitions are reported which are in very good agreement with the simulated spectra at the TDDFT level. As expected from the molecular orbitals involved in the transitions, the red-shifts of the transitions are more pronounced for the S1 state compared to those of unsubstituted pyrene. While a ns-lifetime is observed for the S1 state, the lifetime decreases to 3 ps or less for the origin of the S2 state, indicating a strong interaction between the two states. For the dimer, a slightly V-shaped structure was computed, and intermolecular interactions are dominated by dispersion rather than hydrogen-bonding. The highest oscillator strength was computed for the transition to the S4 state, which deactivates within 4 ps to a lower-lying excited state.

@article{D0NJ02391D, abstract = {We investigated isolated 2-hydroxypyrene and its dimer in the gas phase by time- and frequency-resolved photoionisation with picosecond time-resolution. The experiments are supported by simulations that include an extensive conformational search based on the machine learning ANI-1ccx neural network potential combined with automatic structure classification using a data clustering algorithm. Vibrationally resolved spectra of the S1 ← S0 and S2 ← S0 transitions are reported which are in very good agreement with the simulated spectra at the TDDFT level. As expected from the molecular orbitals involved in the transitions{,} the red-shifts of the transitions are more pronounced for the S1 state compared to those of unsubstituted pyrene. While a ns-lifetime is observed for the S1 state{,} the lifetime decreases to 3 ps or less for the origin of the S2 state{,} indicating a strong interaction between the two states. For the dimer{,} a slightly V-shaped structure was computed{,} and intermolecular interactions are dominated by dispersion rather than hydrogen-bonding. The highest oscillator strength was computed for the transition to the S4 state{,} which deactivates within 4 ps to a lower-lying excited state.}, added-at = {2020-06-26T12:56:30.000+0200}, author = {Schmitt, Hans-Christian and Fischer, Ingo and Ji, Lei and Merz, Julia and Marder, Todd B. and Hoche, Joscha and Röhr, Merle I. S. and Mitric, Roland}, biburl = {https://www.bibsonomy.org/bibtex/23e83754240d092dd1c9be042e00c4919/sagasucy}, doi = {10.1039/D0NJ02391D}, interhash = {9a4fd893ae3a58203c040cd0dadceef2}, intrahash = {3e83754240d092dd1c9be042e00c4919}, journal = {New J. Chem.}, keywords = {ag_pub1}, pages = {-}, publisher = {The Royal Society of Chemistry}, timestamp = {2021-01-11T13:52:51.000+0100}, title = {Isolated 2-hydroxypyrene and its dimer: a frequency- and time-resolved spectroscopic study}, url = {http://dx.doi.org/10.1039/D0NJ02391D}, year = 2020 }