Modulation of the L-a/L-b Mixing in an Indole Derivative: A Position Dependent Study Using 4-, 5-, and 6-Fluoroindole

Autor(en)

Josefin Wilke, Martin Wilke, Christian Brand, J. Dominik Spiegel, Christel M. Marian, Michael Schmitt

Abstrakt

The lowest two electronically excited singlet states of indole and its derivatives are labeled as L-a or L-b, based on the orientation of the transition dipole moment (TDM) and the magnitude of the permanent electric dipole moment. Rotationally resolved electronic Stark spectroscopy in combination with high level ab initio calculations offers the possibility to determine these characteristics and thus the electronic nature of the excited states. In the present contribution this approach was pursued for the systems 4- and 6-fluoroindole and the results compared to the previously investigated system 5-fluoroindole. Changing the position of the fluorine atom from 5 to 4 or 6 is accompanied by an increasing amount of L-a character in the S-1 state. This dramatically influences the orientation of the TDM and erases its ability to be a reasonable identifier of the nature of the excited states for both molecules. However, for 4-fluoroindole, where the influence of the La is weak, the nature of the S1 state can still be assigned to be mainly L-b based on the excited state dipole moment. For 6-fluoroindole, this is not the case anymore, and the L-a/L-b nomenclature completely breaks down due to heavily mixed excited states.

Organisation(en)

Quantenoptik, Quantennanophysik und Quanteninformation

Externe Organisation(en)

Heinrich-Heine-Universität Düsseldorf

Journal

The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory

Band

121

Seiten

1597-1606

Anzahl der Seiten

10

ISSN

1089-5639

DOI

https://doi.org/10.1021/acs.jpca.6b12605

Publikationsdatum

03-2017

Peer-reviewed

Ja

ÖFOS 2012

103025 Quantenmechanik, 104017 Physikalische Chemie

Schlagwörter

ASJC Scopus Sachgebiete

Physical and Theoretical Chemistry

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/a6b31a75-6324-4e24-9a0b-ffd39312d34d