TY  - THES
A1  - Issler, Kevin
T1  - Theory and simulation of ultrafast autodetachment dynamics and nonradiative relaxation in molecules
T1  - Theorie und Simulation der ultraschnellen Autodetachment-Dynamik und nicht-radiativen Relaxation in Molekülen
N2  - In this thesis, theoretical approaches for the simulation of electron detachment processes in molecules following vibrational or electronic excitation are developed and applied. These approaches are based on the quantum-classical surface-hopping methodology, in which nuclear motion is treated classically as an ensemble of trajectories in the potential of quantum-mechanically described electronic degrees of freedom.
N2  - Im Rahmen dieser Arbeit werden theoretische Verfahren zur Simulation von molekularen Ionisierungsprozessen nach elektronischer oder Schwingungsanregung entwickelt und angewendet. Diese Verfahren basieren auf der quanten-klassischen Surface-Hopping-Methode, in welcher die Kernbewegung durch ein Ensemble klassischer Trajektorien im Potenzial quantenmechanisch beschriebener Elektronen behandelt wird.
KW  - Theoretische Chemie
KW  - Autodetachment
KW  - Nonadiabatic Dynamics
KW  - Theoretical Chemistry
KW  - Computational Chemistry
KW  - Relaxation
KW  - Molekül
Y1  - 2024
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-352232
ER  - 
TY  - JOUR
A1  - Hirsch, Florian
A1  - Pachner, Kai
A1  - Fischer, Ingo
A1  - Issler, Kevin
A1  - Petersen, Jens
A1  - Mitric, Roland
A1  - Bakels, Sjors
A1  - Rijs, Anouk M.
T1  - Do Xylylenes Isomerize in Pyrolysis?
JF  - ChemPhysChem
N2  - We report infrared spectra of xylylene isomers in the gas phase, using free electron laser (FEL) radiation. All xylylenes were generated by flash pyrolysis. The IR spectra were obtained by monitoring the ion dip signal, using a IR/UV double resonance scheme. A gas phase IR spectrum of para‐xylylene  was recorded, whereas ortho‐ and meta‐xylylene were found to partially rearrange to benzocyclobutene and styrene. Computations of the UV oscillator strength  for all molecules were carried out and provde an explanation for the observation of the isomerization products.
KW  - biradicals
KW  - high-temperature chemistry
KW  - IR spectroscopy
KW  - pyrolysis
KW  - xylylene
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-218316
VL  - 21
IS  - 14
SP  - 1515
EP  - 1518
ER  - 
TY  - INPR
A1  - Röder, Anja
A1  - Petersen, Jens
A1  - Issler, Kevin
A1  - Fischer, Ingo
A1  - Mitric, Roland
A1  - Poisson, Lionel
T1  - Exploring the Excited-State Dynamics of Hydrocarbon Radicals, Biradicals and Carbenes using Time-Resolved Photoelectron Spectroscopy and Field-Induced Surface Hopping Simulations
T2  - The Journal of Physical Chemistry A
N2  - Reactive hydrocarbon molecules like radicals, biradicals and carbenes are not only key players in combustion processes and interstellar and atmospheric chemistry, but some of them are also important intermediates in organic synthesis. These systems typically possess many low-lying, strongly coupled electronic states. After light absorption, this leads to rich photodynamics characterized by a complex interplay of nuclear and electronic motion, which is still not comprehensively understood and not easy to investigate both experimentally and theoretically. In order to elucidate trends and contribute to a more general understanding, we here review our recent work on excited-state dynamics of open-shell hydrocarbon species using time-resolved photoelectron spectroscopy and field-induced surface hopping simulations, and report new results on the excited-state dynamics of the tropyl and the 1-methylallyl radical. The different dynamics are compared, and the difficulties and future directions of time-resolved photoelectron spectroscopy and excited state dynamics simulations of open-shell hydrocarbon molecules are discussed.
KW  - Excited state dynamics
KW  - Hydrocarbon radicals
KW  - time-resolved photoelectron spectroscopy
KW  - field-induced surface hopping
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-198734
UR  - https://doi.org/10.1021/acs.jpca.9b06346
N1  - This document is the unedited Author’s version of a  Submitted Work that was subsequently accepted for  publication in Journal of Physical Chemistry A, copyright © American Chemical Society after peer review. To access the final edited and published work see Journal of Physical Chemistry A 2019, 123, 50, 10643-10662. https://doi.org/10.1021/acs.jpca.9b06346.
ER  -