@phdthesis{Huegel2018, author = {H{\"u}gel, Markus}, title = {The control of nanomorphology in star-shaped mesogens}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165321}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2018}, abstract = {Stilbene-based star-shaped mesogens have been synthesized with and without fullerene guests. Thermotropic properties and the mechanism of space-filling in the mesophases of these systems have been examined.}, subject = {Fl{\"u}ssigkristall}, language = {en} } @phdthesis{Roos2021, author = {Roos, Markus}, title = {Synthesis, Photophysics and Photocatalysis of [FeFe] Complex Containing Dyads and Bimolecular Systems}, doi = {10.25972/OPUS-23453}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234537}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {In the course of this work, a total of three photocatalytically active dyads for proton reduction could be synthesized together with the associated individual components. Two of them, D1 and D2, comprised a [Ru(bpy)3]2+ photosensitizer and D3 an [Ir(ppy)2bpy]+ photosensitizer. A Ppyr3-substituted propyldithiolate [FeFe] complex was used as catalyst in all systems. The absorption spectroscopic and electrochemical investigations showed that an inner-dyadic electronic coupling is effectively prevented in the dyads due to conjugation blockers within the bridging units used. The photocatalytic investigations exhibited that all dyad containing two-component systems (2CS) showed a significantly worse performance than the corresponding bimolecular three-component systems (3CS). Transient absorption spectroscopy showed that the 2CS behave very similarly to the associated multicomponent systems during photocatalysis. The electron that was intended for the intramolecular transfer from the photosensitizer unit to the catalyst unit within the dyads remains at the photosensitizer for a relatively long time, analogous to the 3CS and despite the covalently bound catalyst. It is therefore assumed that this intramolecular electron transfer is likely to be hindered as a result of the weak electronic coupling caused by the bridge units used. Instead, the system bypasses this through an intermolecular transfer to other dyad molecules in the immediate vicinity. In addition, with the help of emission quenching experiments and electrochemical investigations, it could be clearly concluded that all investigated systems proceed via the reductive quenching mechanism during photocatalysis.}, subject = {Fotokatalyse}, language = {en} }