@PhdThesis{diss_mods_00011184,
  author = 	{Sch{\"o}nborn, Jan Boyke},
  title = 	{Dynamics of photoinduced switching processes},
  year = 	{2013},
  publisher = 	{Christian-Albrechts-Universit{\"a}t zu Kiel},
  address = 	{Kiel},
  keywords = 	{theoretical chemistry; computational chemistry; multiconfigurational; multireferential; semiempirics; ab-initio; direct nuclear dynamics; nuclear quantum dynamics; photochemistry; photorelaxation; molecular switches; theoretische Chemie; Computerchemie; multiconfigurationell; multireferentiell; Semiempirie; direkte Kerndynamik; Kernquantendynamik; Photochemie; molekulare Schalter},
  abstract = 	{The field of molecular photo-isomerisable switches has drawn major interest recently. Molecules which can efficiently and reversibly be transformed from one form to another by light are promising for use in molecular electronics, data-storage or as motors in molecular machines. 
The topic of this thesis are two important classes of molecular switches: Firstly electrocyclic ring-closure/-opening switches, which are represented by 1,3,5-hexatriene/2,4-cyclohexadiene, furylfulgides and a newly developed class of dilactames, and secondly E/Z-isomerisable switches based on azobenzene or a closely related compound, represented by a diazocine, azobenzene oligomeres coupled by a amino group and an azopyridin functionalised nickel porphyrin. 
Due to the complexity of the photo-isomerisation processes, a variety of different multi- and single-determinant static ab-initio methods and semiempirical direct dynamics are used to investigate the systems at hand.
A two-dimensional quantum-dynamical study is presented on an ab-initio potential energy surface with thus far unachieved agreement with experiment. It is used to challenge 2,4-cyclohexadiene as a model system for other electrocyclic switches, implying the need for high-dimensional dynamics studies for the description of the high-energy isomerisation processes. 
The applicability of the semiempirical MRCI-OM3 method to more complicated electrocyclic switches is proven by a comparison to accurate ab-initio and experimental data. Using direct dynamics simulations with this method, the reasons for the differences between the ring-closure reactions of E-isopropyl- and E-methyl-furylfulgide are unravelled. Additionally, static simulations are used to study unusual electronic wave function changes in the isomerisation of Z-methyl-furylfulgide to the E-form and to understand the broad and structured absorption band of cyclic furylfulgides at about 450 nm, which is found to be linked to the excited-state nuclear wave function. Concluding the presented studies of electrocyclic switches, a new class of switches is designed from scratch and studied by static and dynamic means.
The studies of azobenzene-based systems presented here are accurate ab-initio calculations that support theoretical and experimental studies of diazocine dynamics done by collaborators at Kiel University, the assessment of the applicability of the MRCI-OM2 model to 4-aminoazobenzene and bis-[4-(phenylazo)phenyl]amine, a detailed CC2 study of the electronic states of the EEE-tris-[4-(phenyl-azo)phenyl]amine and the two aforementioned systems, and a multiconfigurational study of the electronic states that might facilitate the photo-isomerisation of an azopyridin moiety in a nickel porphyrin complex that leads to a spin state change from singlet to triplet.},
  url = 	{https://macau.uni-kiel.de/receive/diss_mods_00011184},
  file = 	{:https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00004694/diss_jbschoenborn.pdf:PDF},
  language = 	{en}
}