@phdthesis{Preitschopf2023, author = {Preitschopf, Tobias}, title = {Disentangling the Formation of PAHs in Extreme Environments by IR/UV Double Resonance Spectroscopy}, doi = {10.25972/OPUS-32279}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322791}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Polycyclic Aromatic Hydrocarbons (PAHs) are considered as key building blocks in the formation of carbonaceous particles such as soot. In our immediate surroundings, they are mainly generated in incomplete combustion processes and are further considered as carriers of the Unidentified Infrared Bands which are detected in a wide variety of astrophysical envelopes in the interstellar medium. Currently, astrochemical as well as combustion related models favour small resonance stabilized radicals (RSR) as major contributors to PAHs in sequential reactions. Therefore, we generated two RSR under well-defined conditions to investigate their contribution to PAH formation in a pyrolysis microreactor. The various reaction products were identified by IR/UV ion dip spectroscopy which combines the mass-selectivity of UV light with the structural sensitivity of IR radiation. Finally, we investigated the intermolecular interactions in azaphenanthrene dimers in combination with high-level theoretical calculations and found a preferential formation of pi-stacked van der Waals cluster in a molecular jet expansion.}, subject = {Infrarotspektroskopie}, language = {en} }