@phdthesis{Bischof2022, author = {Bischof, Tobias Christian}, title = {Synthese und Reaktivit{\"a}t von borfunktionalisierten Dodecaboranen}, doi = {10.25972/OPUS-28705}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-287059}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Im Rahmen der vorliegenden Arbeit wurden vier Verbindungsklassen - Borylene, Borole, 9-Borafluorene und 9-Aluminafluorene - untersucht und neue Vertreter dieser Klassen, substituiert mit einem ortho-Dicarba-closo-dodecaboran, dargestellt und auf ihre Reaktivit{\"a}t hin untersucht. Dabei sollte mit den speziellen chemischen Eigenschaften des Carboranylsubstituenten, wie dem elektronenziehenden und gleichzeitig σ-aromatischen Charakter, eine erh{\"o}hte Reaktivit{\"a}t der Zielverbindung erreicht werden.}, subject = {Dodecaborane}, language = {de} } @phdthesis{Krebs2023, author = {Krebs, Johannes Heinrich}, title = {Investigation of Dicarba-closo-dodecaborane as a Substituent on Three-coordinate Boron and as an Acceptor in a Pyrene-Donor-Acceptor System}, doi = {10.25972/OPUS-28675}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286758}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {1. Bis(1-(4-tolyl)-carboran-2-yl)-(4-tolyl)-borane, a new bis(o-carboranyl)-(R)-borane 1 was synthesised by lithiation of the o-carboranyl precursor and subsequent salt metathesis reaction with (4-tolyl)BBr2. Cyclic voltammetry experiments on 1 show multiple distinct reduction events with a one-electron first reduction. In a selective reduction experiment the corresponding paramagnetic radical anion 1•- was isolated and characterized. Single-crystal structure analyses allow an in-depth comparison of 1, 1•-, their calculated geometries, and the S1 excited state of 1. 2. The choice of backbone linker for ortho-bis-(9-borafluorene)s has a great influence on the LUMO located at the boron centers and therefore the reactivity of the respective compounds. Herein, we report the room temperature rearrangement of 1,2-bis-(9-borafluorenyl-)-ortho-carborane, C2B10H10-1,2-[B(C12H8)]2 ([2a]) featuring o-carborane as the inorganic three-dimensional backbone and the synthesis of 1,2-bis-(9-borafluorenyl-)benzene, C6H4-1,2-[B(C12H8)]2 (2b) its phenylene analog. DFT calculations on the transition state for the rearrangement support an intramolecular C-H bond activation process via an SEAr-like mechanism in [2a], and predicted that the same rearrangement would take place in 2b, but at elevated temperatures, which indeed proved to be the case. 3. We synthesized 4 a julolidine-like pyrenyl-o-carborane, with pyrene substituted at the 2,7-positions on the HOMO/LUMO nodal plane, continuing our research. Using solid state molecular structures, photophysical data, cyclic voltammetry, DFT and TD-DFT calculations we compare o-carborane and the B(mes)2 (mes = 2,4,6-Me3C6H2) as acceptor groups and confirm the julolidine-like donor strength.}, subject = {closo-Borane}, language = {en} }