@phdthesis{Mahlmeister2023, author = {Mahlmeister, Bernhard}, title = {Twisted Rylene Bisimides for Organic Solar Cells and Strong Chiroptical Response in the Near Infrared}, doi = {10.25972/OPUS-34610}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346106}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The chirality of the interlocked bay-arylated perylene motif is investigated upon its material prospect and the enhancement of its chiroptical response to the NIR spectral region. A considerable molecular library of inherently chiral perylene bisimides (PBIs) was utilized as acceptors in organic solar cells to provide decent device performances and insights into the structure-property relationship of PBI materials within a polymer blend. For the first time in the family of core-twisted PBIs, the effects of enantiopurity on the device performance was thoroughly investigated. The extraordinary structural sensitivity of CD spectroscopy served as crucial analytical tool to bridge the highly challenging gap between molecular properties and device analytics by proving the excitonic chirality of a helical PBI dimer. The chirality of this perylene motif could be further enhanced on a molecular level by both the expansion and the enhanced twisting of the π-scaffold to achieve a desirable strong chiroptical NIR response introducing a new family of twisted QBI-based nanoribbons. These achievements could be substantially further developed by expanding this molecular concept to a supramolecular level. The geometrically demanding supramolecular arrangement necessary for the efficient excitonic coupling was carefully encoded into the molecular design. Accordingly, the QBIs could form the first J-type aggregate constituting a fourfold-stranded superhelix of a rylene bisimide with strong excitonic chirality. Therefore, this thesis has highlighted the mutual corroboration of experimental and theoretical data from the molecular to the supramolecular level. It has demonstrated that for rylene bisimide dyes, the excitonic contribution to the overall chiroptical response can be designed and rationalized. This can help to pave the way for new organic functional materials to be used for chiral sensing or chiral organic light-emitting devices.}, subject = {Molek{\"u}l}, language = {en} } @phdthesis{Mahl2023, author = {Mahl, Magnus}, title = {Polycyclic Aromatic Dicarboximides as NIR Chromophores, Solid-State Emitters and Supramolecular Host Platforms}, doi = {10.25972/OPUS-23462}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234623}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The present thesis introduce different synthetic strategies towards a variety of polycyclic aromatic dicarboximides (PADIs) with highly interesting and diverse properties. This included tetrachlorinated, tetraaryloxy- and tetraaryl-substituted dicarboximides, fused acceptor‒donor(‒acceptor) structures as well as sterically shielded rylene and nanographene dicarboximides. The properties and thus the disclosure of structure‒property relationships of the resulting dyes were investigated in detail among others with UV‒vis absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry and single crystal X-ray analysis. For instance, some of the fused and substituted PADIs offer strong absorption of visible and near infrared (NIR) light, NIR emission and low-lying LUMO levels. On the contrary, intriguing optical features in the solid-state characterize the rylene dicarboximides with their bulky N-substituents, while the devised sterically enwrapped nanographene host offered remarkable complexation capabilities in solution.}, subject = {Organische Chemie}, language = {en} }