TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Liu, Quan
A1  - Wackenhut, Frank
A1  - Wang, Liangxuan
A1  - Hauler, Otto
A1  - Roldao, Juan Carlos
A1  - Adam, Pierre-Michel
A1  - Brecht, Marc
A1  - Gierschner, Johannes
A1  - Meixner, Alfred
T1  - Direct observation of structural heterogeneity and tautomerization of single hypericin molecules
JF  - The journal of physical chemistry letters
N2  - Tautomerization is a fundamental chemical reaction which involves the relocation of a proton in the reactants. Studying the optical properties of tautomeric species is challenging because of ensemble averaging. Many molecules, such as porphines, porphycenes, or phenanthroperylene quinones, exhibit a reorientation of the transition dipole moment (TDM) during tautomerization, which can be directly observed in single-molecule experiments. Here, we study single hypericin molecules, which is a prominent phenanthroperylene quinone showing antiviral, antidepressive, and photodynamical properties. Observing abrupt flipping of the image pattern combined with time-dependent density functional theory calculations allows drawing conclusions about the coexistence of four tautomers and their conversion path. This approach allows the unambiguous assignment of a TDM orientation to a specific tautomer and enables the determination of the chemical structure in situ. Our approach can be applied to other molecules showing TDM reorientation during tautomerization, helping to gain a deeper understanding of this important process.
Y1  - 2021
SN  - 1948-7185
SS  - 1948-7185
U6  - https://doi.org/10.1021/acs.jpclett.0c03459
DO  - https://doi.org/10.1021/acs.jpclett.0c03459
VL  - 12
IS  - 3
SP  - 1025
EP  - 1031
S1  - 7
PB  - ACS
CY  - Washington, DC
ER  -