@phdthesis{Kirchwehm2013, author = {Kirchwehm, Yvonne}, title = {Untersuchungen zur Synthese aromatisch anellierter Triquinacene}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85088}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {In dieser Arbeit wurde ein geeigneter Zugang zu TBTQ-Derivaten erarbeitet, der eine paarweise Funktionalisierung der aromatischen Positionen in direkter Nachbarschaft zum Triquinacen-Kern zul{\"a}sst. Hierf{\"u}r wurde sowohl die doppelte Cyclodehydratisierungsroute als auch die dreifache Cyclisierungsvariante zur Darstellung von Tribenzotriquinacenen dahingehend modifiziert, dass die Einf{\"u}hrung der „ortho"-Substituenten bereits zu Beginn der Synthese mit den Edukten erfolgte, da eine nachtr{\"a}gliche Funktionalisierung der gew{\"u}nschten Positionen am TBTQ aufgrund sterischer Faktoren nicht m{\"o}glich ist. Es wurden unter anderem die ersten literaturbekannten „ortho"-substituierten TBTQ-Derivate erhalten und vollst{\"a}ndig charakterisiert. Zur Erweiterung des aromatischen Systems wurden außerdem Benzodiphenanthrenotriquinacen-Vorstufen synthetisiert, die im Falle der doppelten Cyclodehydratisierungsroute Acenapthylen-Derivate lieferten. Benzodiphenanthrenotriquinacen konnte mit Hilfe der dreifachen Cyclisierungsvariante synthetisiert werden. Die Zielmolek{\"u}le sollen als Vorstufen f{\"u}r {\"u}berbr{\"u}ckte aromatisch anellierte Triquinacene dienen.}, subject = {Triquinacenderivate}, language = {de} } @phdthesis{Buschmann2019, author = {Buschmann, Rachel Abigail}, title = {Synthesis of annulated pi-systems based on a tribenzotriquinacene core}, doi = {10.25972/OPUS-19349}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193491}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {The aim of this work was the selective functionalisation of tribenzotriquinacene (TBTQ) in order to extend the aromatic system and tune the electronic properties. The synthesised molecules could be starting materials for a model system of a defective graphene fragment. The "triple cyclisation pathway" by Hopf et al. was adapted and fluorinated tribenzotriquinacenes were synthesised for the first time. Phenanthrene groups were also introduced in other model systems and the crystal structures of phenanthrene functionalised TBTQs were compared with the parent molecules. In addition, the arrangement of TBTQ and centro methyl functionalised TBTQ was investigated on a Ag(111) surface for the first time using scanning transmission microscopy (STM). Different arrangements were observed, depending on the coverage of the surface. The insights gained about the interaction between TBTQs as well as their synthesis provide a foundation for further work and potential applications as components in organic electronic devices.}, subject = {Triquinacenderivate}, language = {en} } @phdthesis{Toksabay2022, author = {Toksabay, Sinem}, title = {Synthesis and on surface self assembly properties of pi extended tribenzotriquinacenes}, doi = {10.25972/OPUS-24573}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245734}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Tribenzotriquinacene (TBTQ) is a polycyclic aromatic framework with a particularly rigid, C3v symmetrical, bowl-shaped core bearing three mutually fused indane wings. It has been discussed as a defect center for a nanographene by Kuck and colleagues. Therefore, extended TBTQ structures are promising models for saturated defect structures in graphene and graphene like molecules and could be used to investigate the role of defects for the electronic properties of graphene. With this motivation, three different pi-extended TBTQ derivatives have been synthesized in this work. Several different Scholl reaction conditions were tried to obtain fully annulated product of hexaphenyl substituted TBTQ. The desired benzannulated TBTQ derivative could not be obtained due to unfavourable electron density in the respective positions of the molecule and increased reactivity of the bay position of the precursor. As an another method for benzannulation is the on-surface synthesis of graphene flakes and can be carried out using electron beams e.g. in a tunneling microscope (STM). According to our previous research, the parent system TBTQ and centro-methyl TBTQ on silver and gold surfaces showed that the gas phase deposition of these molecules gives rise to the formation of highly ordered two-dimensional assemblies with unique structural features. This shows the feasibility for the formation of defective graphene networks starting from the parent structures. Therefore, the same deposition technique was used to deposit Me-TBTQ(OAc)3Ph6, and investigate the molecular self-assembly properties directly on the surface of Cu (111). In summary, the substrate temperature dependent self-assembly of Me-TBTQ(OAc)3Ph6 molecules on Cu(111), shows the following evolution of orientations. At room temperature, molecules form dimers, which construct a higher-coverage honeycomb lattice. Furthermore, one of the acetyl group located in the bay positions of the TBTQ core is cleaved and the remaining two induce the metal-molecule interaction. It was presumed that by increasing the temperature to 393 K, the remaining acetyl and methyl groups would beeliminated from the molecular structure.In addition, the smaller TBTQ-Ph6 molecules preferably lie flat on Cu(111) crystal and allowing the molecules to settle into a C3-symmetry and form a dense hexagonal structure.}, subject = {Triquinacenderivate}, language = {en} }