TY - JOUR
T1 - Electronic Structure Changes of an Aromatic Amine Photoacid along the Förster Cycle
AU - Eckert, Sebastian
AU - Winghart, Marc Oliver
AU - Kleine, Carlo
AU - Banerjee, Ambar
AU - Ekimova, Maria
AU - Ludwig, Jan
AU - Harich, Jessica
AU - Fondell, Mattis
AU - Mitzner, Rolf
AU - Pines, Ehud
AU - Huse, Nils
AU - Wernet, Philippe
AU - Odelius, Michael
AU - Nibbering, Erik T.J.
N1 - Funding Information:
S. Eckert, M.‐O. Winghart, C. Kleine, M. Ekimova, J. Ludwig and E.T.J. Nibbering acknowledge support from the German Science Foundation (Project Nr. DFG—NI 492/11‐1) and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (ERC Grant Agreement N° 788704; E.T.J.N.). A. Banerjee and M. Odelius acknowledges support from the Carl Tryggers Foundation (contract CTS18 : 285) and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement No 860553 and the Swedish Research Council (VR contract 2021‐04521). DATA AVAILABILITY: The data sets generated and analyzed during the current study are available from the corresponding author on reasonable request. The calculations were enabled by resources provided by the Swedish National Infrastructure for Computing (SNIC) partially funded by the Swedish Research Council through grant agreement no. 2018‐05973. J. Harich and N. Huse gratefully acknowledge funding from the Deutsche Forschungsgemeinschaft within the Sonderforschungsbereich 925 (project A4). E. Pines acknowledges support from the Israel Science Foundation (grant number 1587/16). We all greatly acknowledge the support of the BESSYII staff during x‐ray measurements at the UE52_SGM Undulator SGM variable polarisation beamline of the Helmholtz‐Zentrum Berlin and we thank Helmholtz‐Zentrum Berlin for the allocation of synchrotron radiation beamtime. Open Access funding enabled and organized by Projekt DEAL.
Publisher Copyright:
© 2022 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
PY - 2022/3/24
Y1 - 2022/3/24
N2 - Photoacids show a strong increase in acidity in the first electronic excited state, enabling real-time studies of proton transfer in acid-base reactions, proton transport in energy storage devices and biomolecular sensor protein systems. Several explanations have been proposed for what determines photoacidity, ranging from variations in solvation free energy to changes in electronic structure occurring along the four stages of the Förster cycle. Here we use picosecond nitrogen K-edge spectroscopy to monitor the electronic structure changes of the proton donating group in a protonated aromatic amine photoacid in solution upon photoexcitation and subsequent proton transfer dynamics. Probing core-to-valence transitions locally at the amine functional group and with orbital specificity, we clearly reveal pronounced electronic structure, dipole moment and energetic changes on the conjugate photobase side. This result paves the way for a detailed electronic structural characterization of the photoacidity phenomenon.
AB - Photoacids show a strong increase in acidity in the first electronic excited state, enabling real-time studies of proton transfer in acid-base reactions, proton transport in energy storage devices and biomolecular sensor protein systems. Several explanations have been proposed for what determines photoacidity, ranging from variations in solvation free energy to changes in electronic structure occurring along the four stages of the Förster cycle. Here we use picosecond nitrogen K-edge spectroscopy to monitor the electronic structure changes of the proton donating group in a protonated aromatic amine photoacid in solution upon photoexcitation and subsequent proton transfer dynamics. Probing core-to-valence transitions locally at the amine functional group and with orbital specificity, we clearly reveal pronounced electronic structure, dipole moment and energetic changes on the conjugate photobase side. This result paves the way for a detailed electronic structural characterization of the photoacidity phenomenon.
KW - Aromaticity
KW - Electronic Structure
KW - Orbital Interactions
KW - Photoacids
KW - Time-Resolved Soft x-Ray Spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85128814032&partnerID=8YFLogxK
U2 - 10.1002/anie.202200709
DO - 10.1002/anie.202200709
M3 - Article
C2 - 35325500
SN - 1433-7851
VL - 61
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 27
M1 - e202200709
ER -