@phdthesis{Ceymann2016,
  author    = {Ceymann, Harald},
  title     = {Synthesis and Optical Spectroscopic Properties of Squaraine Superchromophores},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136850},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {In this work the successful synthesis, the linear and nonlinear spectroscopic properties as well as the electrochemical behaviour of some linear and star-shaped squaraine superchromophores that are based on indolenine derivatives were presented. The attempt to synthesise similar chromophores which contained only benzothiazole squaraines failed unfortunately. However, one trimer that contained mixed benzothiazole indolenine squaraines could be synthesised and investigated as well. The linear spectroscopic properties, like red-shift and broadening of the absorption, of all superchromophores could be explained by exciton coupling theory. The heterochromophores (SQA)2(SQB)-N, (SQA)(SQB)2-N and (SQA)(SQB)-NH displayed additional to the typical squaraine fluorescence from the lowest excited state some properties that could be assigned to localised states. While the chromophores with N-core showed very small emission quantum yields, the chromophores with the other cores and the linear oligomers display an enhancement compared to the monomers. Transient absorption spectroscopy experiments of the star-shaped superchromophores showed, that their formally degenerated S1 states are split due to a deviation of the ideal C3 symmetry. This is also the reason for the observation of an absorption band for the highest exciton state, which is derived from the S1-state of the monomers, as its transition-dipole moment would be zero in the symmetrical case. The linear oligomers and the star-shaped superchromophores with a benzene or triarylamine core showed at least additive, sometimes even weak cooperative, behaviour in the two-photon absorption experiments. Additional to higher two-photon absorption cross sections the chromophores showed a pronounced broadening of the nonlinear absorption, due to symmetry breaking and a higher density of states. Unfortunately it was not possible to solve the problem of the equilibrium of the cisoid and the transoid structure of donor substituted azulene squaraines, due to either instability of the squaraines or steric hindrance.},
  subject      = {Squaraine},
  language  = {en}
}
@phdthesis{Macha2016,
  author    = {Macha, Bret B.},
  title     = {Boron-Containing Aromatics as Communicating and Communicative Units in π-Conjugated Systems},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-137498},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {Project Borylene A new borylene ligand ({BN(SiMe\(_3\))(t-Bu)}) has been successfully synthesized bound in a terminal manner to base metal scaffolds of the type [M(CO)\(_5\)] (M = Cr, Mo, and W), yielding complexes [(OC)\(_5\)Cr{BN(SiMe\(_3\))(t-Bu)}] (19), [(OC)\(_5\)Mo{BN(SiMe\(_3\))(t- Bu)}] (20), and [(OC)\(_5\)W{BN(SiMe\(_3\))(t-Bu)}] (21) (Figure 5-1). Synthesis of complexes 19, 20, and 21 was accomplished by double salt elimination reactions of Na\(_2\)[M(CO)\(_5\)] (M = Cr (11), Mo (1), and W (12)) with the dihaloborane Br\(_2\)BN(SiMe\(_3\))(t-Bu) (18). This new "first generation" unsymmetrical borylene ligand is closely akin to the bis(trimethylsilyl)aminoborylene ligand and has been shown to display similar structural characteristics and reactivity. The unsymmetrical borylene ligand {BN((SiMe\(_3\))(t-Bu)} does display some individual characteristics of note and has experimentally been shown to undergo photolytic transfer to transition metal scaffolds in a more rapid manner, and appears to be a more reactive borylene ligand, than the previously published symmetrical {BN(SiMe\(_3\))\(_2\)} ligand, based on NMR and IR spectroscopic evidence. Photolytic transfer reactions with this new borylene ligand ({BN((SiMe\(_3\))(t-Bu)}) were conducted with other metal scaffolds, resulting in either complete borylene transfer or partial transfer to form bridging borylene ligand interactions between the two transition metals. The unsymmetrical ligand's coordination to early transition metals (up to Group 6) indicates a preference for a terminal coordination motif while bound to these highly Lewis acidic species. The ligand appears to form more energetically stable bridging coordination modes when bound to transition metals with high Lewis basicity (beyond Group 9) and has been witnessed to transfer to transition metal scaffolds in a terminal manner and subsequently rearrange in order to achieve a more energetically stable bridging final state. Figure 5-2 lists the four different transfer reactions conducted between the chromium borylene species [(OC)\(_5\)Cr{BN(SiMe\(_3\))(t-Bu)}] (19) and the transition metal complexes [(η\(^5\)-C\(_5\)H\(_5\))V(CO)\(_4\)] (51), [(η\(^5\)-C\(_5\)Me\(_5\))Ir(CO)\(_2\)] (56), [(η\(^5\)-C\(_5\)H\(_4\)Me)Co(CO)\(_2\)] (59), and [{(η\(^5\)-C\(_5\)H\(_5\))Ni}\(_2\){μ-(CO)\(_2\)}] (53). These reactions successfully yielded the new "second generation" borylene complexes [(η\(^5\)-C\(_5\)H\(_5\))(OC)\(_3\)V{BN(SiMe\(_3\))(t-Bu)}] (55), [(η\(^5\)-C\(_5\)Me\(_5\))Ir{BN(SiMe\(_3\))(t-Bu)}\(_2\)] (58), [{(η\(^5\)-C\(_5\)H\(_4\)Me)Co}\(_2\)(μ-CO)\(_2\){μ- BN(SiMe\(_3\))(t-Bu)}] (61), and [{(η\(^5\)-C\(_5\)H\(_5\))Ni}\(_2\)(μ-CO){μ-BN(SiMe\(_3\))(t-Bu)}] (62), respectively. Analysis of the accumulated data for all of the terminal borylene species discussed in this section, particularly bond distances, infrared spectroscopy, and \(^{11}\)B{\(^1\)H} NMR spectroscopic data, has been performed, and a trend in the data has led to the following conclusions: [1] NMR spectroscopic data for the \(^{11}\)B{\(^1\)H} boron and \(^{13}\)C{\(^1\)H} carbonyl environments of the first generation borylene species ([(OC)\(_5\)M{BN(SiMe\(_3\))(t-Bu)}] (M = Cr (19), Mo (20), and W (21))) all show progressive up-field shifting as the Group 6 metal becomes heavier (Cr (19) to Mo (20) to W (21)), indicating maximum deshielding for these nuclei in the [(OC)\(_5\)Cr{BN(SiMe\(_3\))(t-Bu)}] (19) complex. [2] The boron-metal-trans-carbon (B-M-C\(_{trans}\)) axes of the first generation borylene complexes [(OC)\(_5\)M{BN(SiMe\(_3\))(t-Bu)}] (M = Mo (20), and W (21)) are not completely linear, preventing direct IR spectroscopic comparison. The chromium analog [(OC)\(_5\)Cr{BN(SiMe\(_3\))(t-Bu)}] (19), however, is essentially linear and displays the expected three carbonyl IR stretching frequencies, all at higher energy than those of the chromium bis(trimethylsilyl)aminoborylene complex [(OC)\(_5\)Cr{BN(SiMe\(_3\))\(_2\)}] (13), indicating that the ({BN(SiMe\(_3\))(t-Bu)}) ligand is either a stronger σ-donor or a poorer π-acceptor compared to the chromium metal center. [3] In transfer reactions, the {BN(SiMe\(_3\))(t-Bu)} fragment appears to be more stable as a terminal ligand when bound to more Lewis acidic first row transition metals and appears to prefer coordination in a bridging motif when coordinated to more Lewis basic first row transition metals. Project Borirene The synthesis of the first platinum bis(borirene) complexes are presented along with findings from structural and electronic examination of the role of platinum in allowing increased coplanarity and conjugation of twin borirene systems. This series of trans-platinum-linked bis(borirene) complexes (119/120, 122/123, and 125/126) all show coplanarity in the twin ring systems and stand as the first verified structural representations of two coplanar borirene systems across a linking unit. The role of a platinum atom in mediating communication between chromophoric ligands can be generalized by an expected bathochromic (red) shift in the absorption spectrum due to an increase in the electronic delocalization between the formerly independent aromatic systems when compared to the platinum mono-σ-borirenyl systems. The trans-platinum bis(borirene) scaffold serves as a simplified monomeric system that allows not only study of the effects of transition metals in mitigating electronic conjugation, but also the tunability of the overall photophysical profile of the system by exocyclic augmentation of the three-membered aromatic ring. A series of trans-platinum bis(alkynyl) complexes were prepared (Figure 5-3) to serve as stable platforms to transfer terminal borylene ligands {BN(SiMe\(_3\))\(_2\)} onto 95, 102, 106, and 63. Mixing of cis-[PtCl\(_2\)(PEt\(_3\))\(_2\)] (93) with two equivalents of corresponding alkynes in diethylamine solutions successfully yielded trans-[Pt(C≡C-Ph)\(_2\)(PEt\(_3\))\(_2\)] (95), trans-[Pt(C≡C-p-C\(_6\)H\(_4\)OMe)\(_2\)(PEt\(_3\))\(_2\)] (102), trans-[Pt(C≡C-p-C\(_6\)H\(_4\)CF\(_3\))\(_2\)(PEt\(_3\))\(_2\)](106), and trans-[Pt(C≡C-9-C\(_{14}\)H\(_9\))\(_2\)(PEt\(_3\))\(_2\)] (63) through salt elimination reactions. Three of the trans-platinum bis(alkynyl) complexes (95, 102, and 106) successfully yielded trans-platinum bis(borirenyl) complexes 119/120, 122/123, and 125/126 through photolytic transfer of two equivalents of the terminal borylene ligand {BN(SiMe\(_3\))\(_2\)} from [(OC)\(_5\)Cr{BN(SiMe\(_3\))\(_2\)}] (13) (Figure 5-4). Attempted borylene transfer reactions to the trans-platinum bis(alkynyl) complex trans-[Pt(C≡C-9-C\(_{14}\)H\(_9\))\(_2\)(PEt\(_3\))\(_2\)] (63) failed due to the complex's photoinstability. Although a host of other variants of platinum alkynyl species were prepared and attempted, these three were the only ones that successfully yielded trans-platinum bis(borirenyl) units. Attempts were also made to create a cis variant for direct UV-vis comparison to the trans-platinum bis(borirenyl) variants, however, these attempts were also not successful. Gladysz-type platinum end-capped alkynyl species were also synthesized to serve as transfer platforms for borirene synthesis in sequential order, however, these species were also shown to not be photolytically stable. A host of new monoborirenes: Ph-(μ-{BN(SiMe\(_3\))(t-Bu)}C=C)-Ph (148), trans- [PtCl{(μ-{BN(SiMe\(_3\))(t-Bu)}C=C)-Ph}(PEt\(_3\))\(_2\)] (149), and [(η\(^5\)-C\(_5\)Me\(_5\))(OC)\(_2\)Fe(μ- {BN(SiMe\(_3\))(t-Bu)}C=C)Ph] (150) were synthesized by photo- and thermolytic transfer of the unsymmetrical {BN(SiMe\(_3\))(t-Bu)} ligand from the complexes [(OC)\(_5\)M{BN(SiMe\(_3\))(t-Bu)}] (M = Cr (19), Mo (20), and W (21)) to organic and organometallic alkynyl species to verify that the borylene complexes all display similar reactivity to the symmetrical terminal borylenes of the type [(OC)\(_5\)M{BN(SiMe\(_3\))\(_2\)}] (M = Cr (13), Mo (14), and W (15)). These monoborirenes are all found to be oils when in their pure states and X-ray structural determination was impossible for these species. Project Boratabenzene The bis(boratabenzene) complex [{(η\(^5\)-C\(_5\)H\(_5\))Co}\(_2\){μ:η\(^6\),η\(^6\)-(BC\(_5\)H\(_5\))\(_2\)}] (189) was successfully prepared by treatment of tetrabromodiborane (65) with six equivalents of cobaltocene (176) in a unique reaction that utilized cobaltocene as both a reagent and reductant (Figure 5-5). The bimetallic transition metal complex features a new bridging bis(boratabenzene) ligand linked through a boron-boron single bond that can manifest delocalization of electron density by providing an accessible LUMO orbital for π-communication between the cobalt centers and heteroaromatic rings. This dianionic diboron ligand was shown to facilitate electronic coupling between the cobalt metal sites, as evidenced by the potential separations between successive single-electron redox events in the cyclic voltammogram. Four formal redox potentials for complex 189 were found: E\(_{1/2}\)(1) = -0.84 V, E\(_{1/2}\)(2) = -0.94 V, E\(_{1/2}\)(3) = -2.09 V, and E\(_{1/2}\)(4) = -2.36 V (relative to the Fc/Fc+ couple) (Figure 5-6). These potentials correlate to two closely-spaced oxidation waves and two well-resolved reduction waves ([(189)]\(^{0/+1}\), [(189)]\(^{+1/+2}\), [(189)]\(^{0/-1}\), and [(189)]\(^{-1/-2}\) redox couples, respectively). The extent of metal-metal communication was found to be relative to the charge of the metal atoms, with the negative charge being more efficiently delocalized across the bis(boratabenzene) unit (class II Robin-Day system). Magnetic studies indicate that the Co(II) ions are weakly antiferromagnetically coupled across the B-B bridge. While reduction of the bis(boratabenzene) system resulted in decomposition of the complex, oxidation of the system by one- and two-electron steps resulted in isolable stable monocationic (194) and dicationic (195) forms of the bis(boratabenzene) complex (Figure 5-7). Study of these systems verified the results of the cyclic voltammetry studies performed on the neutral species. These species are unfortunately not stable in acetonitrile or nitromethane solutions, which until this point are the only solvents that have been observed to dissolve the cationic species. Unfortunately, this instability in solution complicates reactivity studies of these cationic complexes. Finally, reactivity studies were performed on the neutral bis(boratabenzene) complex 189 in which the compound was tested for: (A) cleavage of the boratabenzene (cyclo-BC\(_5\)H\(_5\)) ring from the cobalt center, and (B) oxidative addition of the B-B bond to a transition metal scaffold to attempt synthesis of the first ever L\(_x\)M-η\(^1\)-(BC\(_5\)H\(_5\)) complex. Both of these reactivity studies, however, proved unsuccessful and typically witnessed decomposition of the bis(boratabenzene) complex or no reactivity. After repeated attempts of these reactions, no oxidative addition of the bis(boratabenzene) system could be confirmed.},
  subject      = {Borverbindungen},
  language  = {en}
}
@phdthesis{Buschmann2015,
  author    = {Buschmann, Peter},
  title     = {Anbindung von Katalysatoren an Nanodiamantpartikel mit Hilfe starrer Linker},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132966},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Das Ziel dieser Arbeit war die Herstellung von Diamantmaterialien, deren Oberfl{\"a}chen mit Alkinen, Aziden oder Aldehyden modifiziert waren. Diese funktionellen Gruppen sollten die einfache Anbindung verschiedener katalytisch aktiver Systeme mit Hilfe der 1,3-dipolaren Cycloaddition nach Huisgen bzw. Iminbildung ermg{\"o}glich. Da in einer vorangegangenen Arbeit Hinweise darauf gefunden wurde, dass die hochgradig funktionalisierte Oberfl{\"a}che von Detonationsnanodiamant dazu in der Lage ist, die Aktivit{\"a}t von immobilisierten Katalysatoren zu behindern. Darum wurde in dieser Arbeit verglichen, ob die Verwendung von starren Linkern auf Tolanbasis einen Vorteil gegen{\"u}ber ihren flexiblen Gegenst{\"u}cken liefert. Dazu wurde f{\"u}r jede der oben genannten Funktionalisierungsarten je ein Diamantmaterial mit flexibler sowie mindestens eines mit unbiegsamer Verbindungseinheit hergestellt und getestet. Dadurch konnte das Konzept der starren Linker f{\"u}r Enzyme best{\"a}tigt werden und es wurde eine signifikant h{\"o}here Aktivit{\"a}t erhalten, als wenn flexible Anbindungsbr{\"u}cken verwendet wurden. Bei Organokatalysatoren und metallorganischen Systemen konnten jedoch keine erfolgreichen Katalysen durchgef{\"u}hrt werden.},
  subject      = {Nanopartikel},
  language  = {de}
}
@phdthesis{Gloza2014,
  author    = {Gloza, Steffi},
  title     = {Synthese und Charakterisierung von Anthracen- und Anthrachinon-substituierten sternf{\"o}rmigen Mesogenen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110595},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Im Rahmen der vorliegenden Arbeit wurden promesogene Arme sowie eine Bibliothek von Sternmesogenen mit Anthracen als Donor- und Anthrachinon als Akzeptorbaustein synthetisiert und untersucht. Ein Schwerpunkt der Arbeit lag auf der Synthese, dem Upscaling, der selektiven Sch{\"u}tzung und weiteren Umsetzung der 2,6-substituierten Anthracen- und Anthrachinon-Chromophore zu den Armbausteinen. Besondere Herausforderungen ergaben sich nicht nur in der Entwicklung einer effizienten Synthesestrategie zur Gewinnung der Chromophore, sondern auch in der Wahl geeigneter Schutzgruppen. Die sternf{\"o}rmigen Verbindungen, die im Rahmen der vorliegenden Arbeit pr{\"a}pariert wurden, enthalten 1,3,5-Trihydroxybenzen (Phloroglucin) als Kerneinheit und sind Multiarmmesogene mit der kleinstm{\"o}glichen Zahl an Armen. Durch geeignete Schutzgruppenstrategien gelang neben den C3-symmetrischen Verbindungen die gezielte Darstellung der C2-symmetrischen und unsymmetrischen Verbindungen. Die Gesamtausbeuten der semiperfluorierten Verbindungen fallen deutlich geringer aus als die der ausschließlich mit Alkylketten dekorierten Derivate, da ihre Isolierung sehr anspruchsvoll ist. Alle Verbindungen bilden ausnahmslos kolumnare Phasen. Semiperfluorierte Ketten wurden eingef{\"u}hrt, um eine Trennung des Donors Anthracen und des Akzeptors Anthrachinon zu erreichen. Die Kolumnendurchmesser sind bei allen kolumnaren Mesophasen wesentlich kleiner als die Durchmesser der sternf{\"o}rmigen Konformere der Mesogene. Angelehnt an die fr{\"u}her untersuchten Oligobenzoatsterne werden Modelle mit gefalteten, E-f{\"o}rmigen Konformeren aufgestellt. So ist es m{\"o}glich, die erforderliche Anzahl an Molek{\"u}len pro Elementarzelle in einer dichten, nanosegregierten Packung anzuordnen. Mit Absorptions- und Emissionsmessungen konnte dieses Modell best{\"a}tigt werden. In allen Donor- und Akzeptor-substituierten Verbindungen wird die Fluoreszenz durch Energietransferprozesse nach F{\"o}rster und Dexter fast vollst{\"a}ndig gel{\"o}scht. Restfluoreszenz wird in dem Bereich beobachtet, der nur noch den Transfer nach Dexter zul{\"a}sst und ist f{\"u}r die Derivate am h{\"o}chsten, die in den E-f{\"o}rmigen Konformeren Donor und Akzeptor am besten trennen k{\"o}nnen. Die Ergebnisse dieser Arbeit zeigen, dass Anthracen- und Anthrachinonderivate eine Vielzahl komplexer zwei- und dreidimensional hochgeordneter kolumnarer Strukturen ausbilden und damit hochinteressant sind als fl{\"u}ssigkristalline organische Halbleitermaterialien.},
  subject      = {Fl{\"u}ssigkristall},
  language  = {de}
}
@phdthesis{Dechant2022,
  author    = {Dechant, Moritz Thomas},
  title     = {Synthese und Struktur-Eigenschaftsbeziehungen neuer Phthalocyanin-Sternmesogene - Ein neues Design f{\"u}r organische, fl{\"u}ssigkristalline Photovoltaikmaterialien},
  doi       = {10.25972/OPUS-23888},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238888},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Es wurde eine Vielzahl neuer, fl{\"u}ssigkristalliner Phthalocyanin-Sternmesogene synthetisiert. Die Struktur-Eigenschaftsbeziehungen und die thermotropen Eigenschaften neuer Phthalocyanin-Sternmesogene mit Freiraum sowie von sterisch {\"u}berfrachteten Verbindungen wurden insbesondere hinsichtlich der Freiraumf{\"u}llung untersucht. Diesbez{\"u}glich wurde ein neuer supramolekularer, freiraumf{\"u}llender "Klick-Prozess" zwischen einem Molek{\"u}l mit Freiraum und einem sterisch {\"u}berfrachteten Molek{\"u}l mit vier Fullerenen beobachtet. Die photophysikalischen Eigenschaften wurden zudem insbesondere im Hinblick auf die Anwendung f{\"u}r die Organische Photovoltaik untersucht.},
  subject      = {Phthalocyanin},
  language  = {de}
}
@phdthesis{Bahndorf2022,
  author    = {Bahndorf, Katrin},
  title     = {Synthese und Charakterisierung von Aminos{\"a}ure-basierten Amphiphilen und deren Umsetzung zu C\(_3\)-symmetrischen Sternmesogenen - Strukturkontrolle in weicher Materie {\"u}ber Oligopeptidaggregation},
  doi       = {10.25972/OPUS-25275},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252753},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Synthese einer Bibliothek von Aminos{\"a}ure-basierten Oligopeptid-Amphiphilen mittels Festphasensynthese, deren kovalente Kn{\"u}pfung an einen nukleophilen Kern zu C3-symmetrischen Sternmesogenen und die Analyse der Einfl{\"u}sse der verwendeten Aminos{\"a}uren auf die Sekund{\"a}rstruktur des synthetisierten Molek{\"u}ls.},
  language  = {de}
}
@phdthesis{Doerrich2014,
  author    = {D{\"o}rrich, Steffen},
  title     = {Synthese und Charakterisierung neuartiger Silicium-, Germanium- und zinnorganischer Riechstoffe},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-94552},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Aufbauend auf dem Konzept der C/Si-Bioisosterie beschreibt die vorliegende Arbeit die Synthese und Charakterisierung siliciumhaltiger Derivate der Riechstoffe Galaxolide, Lilial, Bourgeonal, 5,7,7-Trimethyl-4-methylenoctanal und α-Galbanone sowie Beitr{\"a}ge zur Synthese eines silicium¬haltigen Derivats von δ-Damascone. Basierend auf der C/Ge- und C/Sn-Bioisosterie wurden zudem die Germa- und Stanna-Analoga von Lilial und Bourgeonal synthetisiert. Die entsprechenden Zielverbindungen sowie alle isolierten Zwischenstufen wurden durch NMR-Spektroskopie (1H, 11B, 13C, 15N, 29Si, 119Sn) und Elementaranalyse (C, H, N) charakterisiert. In einigen F{\"a}llen erfolgte zus{\"a}tzlich eine Charakterisierung durch Einkristall-R{\"o}ntgenstrukturanalyse oder Infrarot-Spektroskopie.},
  subject      = {Silicium},
  language  = {de}
}
@phdthesis{Meininger2022,
  author    = {Meininger, Markus},
  title     = {Calcium hydroxide as antibacterial implant coating},
  doi       = {10.25972/OPUS-26112},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-261122},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In modern medicine hip and knee joint replacement are common surgical procedures. However, about 11 \% of hip implants and about 7 \% of knee implants need re-operations. The comparison of implant registers revealed two major indications for re-operations: aseptic loosening and implant infections, that both severely impact the patients' health and are an economic burden for the health care system. To address these problems, a calcium hydroxide coating on titanium was investigated in this thesis. Calcium hydroxide is a well-known antibacterial agent and used with success in dentistry. The coatings were applied with electrochemically assisted deposition, a versatile tool that combines easiness of process with the ability to coat complex geometries homogeneously. The pH-gradient during coating was investigated and showed the surface confinement of the coating process. Surface pre-treatment altered the surface morphology and chemistry of the titanium substrates and was shown to affect the morphology of the calcium hydroxide coatings. The influence of the coating parameters stirring speed and current pulsing were examined in various configurations and combinations and could also affect the surface morphology. A change in surface morphology results in a changed adhesion and behavior of cells and bacteria. Thus, the parameters surface pre-treatment, stirring speed and current pulsing presented a toolset for tailoring cellular response and antibacterial properties. Microbiological tests with S. aureus and S. epidermidis were performed to test the time-dependent antibacterial activity of the calcium hydroxide coatings. A reduction of both strains could be achieved for 13 h, which makes calcium hydroxide a promising antibacterial coating. To give insight into biofilm growth, a protocol for biofilm staining was investigated on titanium disks with S. aureus and S. epidermidis. Biofilm growth could be detected after 5 days of bacterial incubation, which was much earlier than the 3 weeks that are currently assumed in medical treatment. Thus, it should be considered to treat infections as if a biofilm were present from day 5 on. The ephemeral antibacterial properties of calcium hydroxide were further enhanced and prolonged with the addition of silver and copper ions. Both ionic modifications significantly enhanced the bactericidal potential. The copper modification showed higher antibacterial effects than the silver modification and had a higher cytocompatibility which was comparable to the pure calcium hydroxide coating. Thus, copper ions are an auspicious option to enhance the antibacterial properties. Calcium hydroxide coatings presented in this thesis have promising antibacterial properties and can easily be applied to complex geometries, thus they are a step in fighting aseptic loosening and implant infections.},
  subject      = {Calciumhydroxid},
  language  = {en}
}
@phdthesis{BruecknergebChristel2019,
  author    = {Br{\"u}ckner [geb. Christel], Theresa},
  title     = {Novel application forms and setting mechanisms of mineral bone cements},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157045},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Calcium phosphate cements (CPC) represent valuable synthetic bone grafts, as they are self-setting, biocompatible, osteoconductive and in their composition similar to the inorganic phase of human bone. Due to their long shelf-life, neutral setting and since water is sufficient for setting, hydroxyapatite (HA) forming cements are processed in different paste formulations. Those comprise dual setting, Ca2+ binding and premixed cement systems. With dual setting formulations, both dissolution and precipitation of the cement raw powder occur simultaneously to the polymerization of water-soluble monomers to form a hydrogel. Chelating agents are able to form complexes with Ca2+ released from the raw powder. Premixed systems mostly contain the raw powder of the cement and a non-aqueous binder liquid which delays the setting reaction until application in the moist physiological environment. In the present work, two of those reaction mechanisms allowed the development of HA based cement applications. Drillable cements are of high clinical interest, as the quality of screw and plate osteosynthesis techniques can be improved by cement augmentation. A drillable, dual setting composite from HA and a poly(2-hydroxyethyl methacrylate) hydrogel was analyzed with respect to the influence of monomer content and powder-to-liquid ratio on setting kinetics and mechanical outcome. While the conversion to HA and crystal growth were constantly confined with increased monomer amount, a minimum concentration of 50 \% was required to see impressive ameliorations including a low bending modulus and high fracture energy at improved bending strength. Increasing the liquid amount enabled injection of the paste as well as drilling after 10 min of pre-setting. While classic bone wax formulations have drawbacks such as infection, inflammation, hindered osteogenesis and a lack of biodegradability, the as-presented premixed formulation is believed to exhibit outmatching properties. It consisted of HA raw powders and a non-aqueous, but water-miscible carrier liquid from poly(ethylene glycol) (PEG). The bone wax was proved to be cohesive and malleable, it withstood blood pressure conditions and among deposition in an aqueous environment, PEG was exchanged such that porous, nanocrystalline HA was formed. Incorporation of a model antibiotic proved the suitability of the novel bone wax formulation for drug release purposes. Prefabricated laminates from premixed carbonated apatite forming cement and poly(ε-caprolactone) fiber mats with defined pore architecture were presented as a potential approach for the treatment of 2-dimensional, curved cranial defects. They are flexible until application and were produced in a layer-by-layer approach from both components such that the polymer scaffold prevents the cement from flowing. It was demonstrated that solution electrospinning with a patterned collector for the fabrication of perforated fiber mats was suitable, as high fiber volume contents in combination with an appropriate interface enabled the successful fabrication of mechanically reinforced laminates. Mild immersion of the scaffolds under alkaline conditions additionally improved the interphase followed by an increase in bending-strength. Since few years, magnesium phosphate cements (MPC) have attracted increasing attention for bone replacement. Compared to CPC, MPC exhibit a higher degradation potential and high early strength and they release biologically valuable Mg2+. However, common systems offer some challenges while using them in non-classic cement formulations such as the need for foreign ion supply, the potential acidity of the reaction or the fast setting kinetics. Here, it was possible to develop a chelate-setting MPC paste with a broad spectrum of potential applications. The general mechanism of the novel setting principle was tested in a proof-of-principle manner. The cement paste consisted of farringtonite with differently concentrated phytic acid solution for chelate formation with Mg2+ from the raw powder. Adjusting the phytic acid content and adding a magnesium oxide as setting regulator to compensate its retarding effect resulted in drillable formulations. Additionally, there is a strong clinical demand for well working bone adhesives especially in a moist environment. Mostly the existing formulations are non-biodegradable. Ex vivo adhesion of the above presented MPC under wet conditions on bone demonstrated over a course of 7 d shear strengths of 0.8 MPa. Further, the hardened cement specimens showed a mass loss of 2 wt.\% within 24 d in an aqueous environment and released about 0.17 mg/g of osteogenic Mg2+ per day. Together with the demonstrated cytocompatibility towards human fetal osteoblasts, this cement system showed promising characteristics in terms of degradable biocements with special application purposes.},
  subject      = {Knochenzement},
  language  = {en}
}
@phdthesis{HechtgebWagener2019,
  author    = {Hecht [geb. Wagener], Reinhard Johannes},
  title     = {Processing and Characterization of Bulk Heterojunction Solar Cells Based on New Organic n-Type Semiconductors},
  doi       = {10.25972/OPUS-16138},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161385},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {This thesis established the fabrication of organic solar cells of DA dye donors and fullerene acceptors under ambient conditions in our laboratory, however, with reduced power conversion efficiencies compared to inert conditions. It was shown that moisture had the strongest impact on the stability and reproducibility of the solar cells. Therefore, utilization of robust materials, inverted device architectures and fast fabrication/characterization are recommended if processing takes place in air. Furthermore, the dyad concept was successfully explored in merocyanine dye-fullerene dyads and power conversion efficiencies of up to 1.14 \% and 1.59 \% were measured under ambient and inert conditions, respectively. It was determined that the major drawback in comparison to comparable BHJ devices was the inability of the dyad molecules to undergo phase separation. Finally, two series of small molecules were designed in order to obtain electron transport materials, using the acceptor-core-acceptor motive. By variation of the acceptor units especially the LUMO levels could be lowered effectively. Investigation of the compounds in organic thin film transistors helped to identify promising molecules with electron transport properties. Electron transport mobilities of up to 7.3 × 10-2 cm2 V-1 s-1 (ADA2b) and 1.39 × 10-2 cm2 V-1 s-1 (AπA1b) were measured in air for the ADA and AπA dyes, respectively. Investigation of selected molecules in organic solar cells proved that these molecules work as active layer components, even though power conversion efficiencies cannot compete with fullerene based devices yet. Thus, this thesis shows new possibilities that might help to develop and design small molecules as substitutes for fullerene acceptors.},
  subject      = {Heterosolarzelle},
  language  = {en}
}
@phdthesis{Rang2023,
  author    = {Rang, Maximilian},
  title     = {Metall{\"a}hnliche Reaktivit{\"a}t \(in\) \(situ\) erzeugter Borylene},
  doi       = {10.25972/OPUS-24046},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240465},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Einfach Lewis-Basen stabilisierte Borylene wurden durch Reduktion in situ hergestellt und in Gegenwart von Kohlenstoffmonoxid oder Distickstoff umgesetzt. Die entstandenen Verbindungen wurden mittels NMR-, ESR-, UV/Vis- und IR-Spektroskopie sowie Einkristallr{\"o}ntgenstrukturanalyse charakterisiert. Im Zuge dessen konnten f{\"u}r die erhaltenen Spezies Eigenschaften ermittelt werden, die denen analoger {\"U}bergangsmetallkomplexe {\"a}hneln. Ferner konnten die zugrundeliegenden mechanistischen Vorg{\"a}nge der Reaktionen durch gezielte Variation der Reaktionsparameter aufgekl{\"a}rt werden. Zudem wurden Redoxverhalten und Reaktivit{\"a}ten der isolierten Produkte in weiterf{\"u}hrenden Studien n{\"a}her untersucht.},
  subject      = {Bor},
  language  = {de}
}
@phdthesis{HerbstgebHoehne2019,
  author    = {Herbst [geb. H{\"o}hne], Stefanie},
  title     = {Liquid Crystalline Perylene Bisimide Assemblies},
  doi       = {10.25972/OPUS-16485},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164857},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Thus, the main focus of this thesis was to generate and investigate new one-dimensional LC PBI J-aggregates of an entirely new PBI organization with the transition dipole moments of the chromophores arranged parallel to the columnar axis and in slipped pi-pi stacking fashion to form highly fluorescent J-aggregates. Towards this goal, the tetra-bay substituted PBI 4c bearing free NH functional groups at the imide positions and four dendrons with branched ethylhexyl alkoxy chains at the meta-position of the phenoxy spacer (Figure 8.1a) was synthesized and compared to a literature known reference PBI 1. The mesogenic dendrons ensure LC character of the dye, which was confirmed by POM, DSC and extensive X-ray analysis. Furthermore, the sterically demanding bay-substituents prevent the cofacial assembly of the chromophores and force the dyes into a slipped pi-stacked order with the main transition dipole moments of the dyes oriented parallel to the columnar axis. X-ray analysis revealed that PBI 4c assembles into columnar triple-stranded helices consisting of side-to-side stacked molecules, which organize into a Colh phase (Figure 8.1b). FT-IR experiments of a thin film and aggregates in MCH solution confirmed the formation of H-bonds between the imide moieties. Temperature-dependent investigations furthermore proved a reversible formation of H-bonds and polarized FT-IR experiments finally gave evidence for the direction of the H-bonds along the shearing respective the columnar axis (Figure 8.1c). This was additionally verified by polarized UV-Vis absorption studies of aligned thin films. The changes in the UV-Vis absorption spectra of concentration- and temperature-dependent experiments in MCH are in agreement with the formation of J-aggregates and could be fitted to a nucleation-elongation growth mechanism. Remarkably, fluorescence spectroscopy studies revealed highly emissive aggregates in solution. These various spectroscopic techniques proved the utilization of directional noncovalent forces like hydrogen-bonding and pi-pi interactions in a cooperative manner forcing the PBI molecules in an unprecedented organization of a slipped pi-stacked arrangement with the orientation of the molecular axis and the respective transition dipole moments parallel to the columns of the LC phase. By the group of Dietrich the formation of exciton-polaritons in imprinted LC pillar microcavities as consequent use of the LC 4c was reported for the first time.In the second part of this thesis the hierarchical organization of LC PBIs into defined single-, double-, triple- and quadruple-stranded J-aggregates within crystalline and columnar LC phases, partially arranged in helical supramolecular structures in dependence of the molecular design was demonstrated. This was achieved via the preparation of a library of twelve molecules PBI 3-6(a-c) (Figure 8.2a) that was synthesized by varying the substitution position of the dendrons at the phenoxy-spacer from ortho to meta or para and by introducing an additional methyl group in ortho-position. Also the length and shape of the alkoxy chains was changed. Consequently, the impact of the sterical demand of the bay substituents concerning their phase properties, molecular arrangement and exciton coupling was investigated. POM, DSC and X-ray studies revealed the formation of only crystalline phase for the ortho-substituted PBIs 3a-c, whereas the other derivatives generated SC or LC phases. The main focus was the series with the n-C12-alkoxy chains. For the corresponding PBIs 4-6b columnar LC phases were confirmed. Retrostructural analysis by modelling and simulations gave indications for a single stranded organization for PBI 3b, a double-stranded helix for PBI 6b, a triple-stranded helical arrangement for PBI 5b and a quadruple-stranded helix for PBI 4b (Figure 8.2b-d). For all four derivatives the same molecular orientation within the columns as for PBI 4c was proven by polarized FT-IR and UV-Vis absorption studies in aligned thin films. The organization in helices of different number of strands in the Cr and LC phases of PBI 3b, 4b, 5b and 6b offered a unique possibility to elucidate the influence of particular packing arrangements on dye aggregate interactions with light. In particular, it can be investigated how exciton coupling of the dyes' transition dipole moments and fluorescence properties are affected. In this context, the spectroscopic properties were investigated in thin film, which revealed a strong bathochromic shift of the absorption maxima compared to the monomers in solution in dependence on the number of strands for PBIs 4-6b in contrast to PBI 3b (Figure 8.2e). The same tendency was observed for the respective aggregates in MCH solution. The spectral changes obtained during concentration- and temperature-dependent UV-Vis absorption studies verified the formation of J-aggregates in MCH solution and solid state. The respective aggregates are highly likely formed via a nucleation-elongation growth mechanism. Appliance of Kasha's exciton theory on the supramolecular aggregates revealed different contributions of H- and J-type coupling for the oligo-stranded helices. Under these considerations, it delivered an explanation for the absorption and fluorescence properties of the assemblies and declares the "best" J-aggregate for the double stranded arrangement of PBI 6b with purely negative couplings among neighbour molecules and a quantum yield above 74 \% of the aggregates in MCH solution. With this H-bonded PBI-based library approach of twelve derivatives it could be shown how molecular engineering of perylene bisimide dyes can be used to design defined, complex supramolecular assemblies with unprecedented packing patterns and concomitant intriguing spectroscopic properties. So far, the formation of defined liquid crystalline supramolecular structures of tetra-bay substituted PBIs by double H-bonding between free imide moieties and pi-pi interactions between the chromophores was demonstrated. The impact of the H-bonds on the molecular arrangement was investigated in the next part of this thesis. In this regard, PBIs 7 and 8 bearing a methyl or cyclohexyl group at the imide position (Figure 8.3a) were synthesized and compared to PBI 4c. The soft character of the solid state for PBIs 7 and 8 was confirmed by POM, DSC and X-ray analysis. The X-ray studies further revealed for both PBIs a change of the molecular assembly towards helical columnar structures of conventional pi-stacked chromophores (Figure 8.3b) when the directed H-bonds cannot contribute as noncovalent interactions to the assembly formation. Temperature-dependent UV-Vis absorption studies demonstrated the importance of H-bonding in MCH solution in the way that the formation of J-aggregates as for PBI 4c could not be observed for the imide substituted molecules. In the next step, the spectroscopic properties in thin film were investigated. For PBI 7 a J-type band and fluorescence spectra with an enlarged Stokes shift and increased fluorescence lifetime of 11.4 ns, compared to PBI 4c, was obtained, suggesting the generation of excimer type emission by considering the assumed conventional stacking of rotational displaced molecules from X-ray analysis. With polarized UV-Vis absorption experiments the orientation of the molecules perpendicular to the shearing direction and subsequently to the columnar axis was confirmed. These diverse investigations clearly demonstrated the imperative of H-bonds for stable, defined, LC J-aggregates with the transition dipole moments parallel to the columnar axis. With PBIs 7 and 8 it is impressively shown how small changes in the molecular structure influence the molecular arrangement dependent on the cooperation of non-covalent interactions like H-bonding and pi-pi stacking. In the last part of this thesis the generation of two-dimensional LC arrangements is presented. Since tetra-bay substituted PBIs lead always to twisted cores preventing lamellar arrangement, here 1,7-disubstitution and the simultaneous retention of the free imide positions was chosen to generate LC lamellar phases of PBIs 9a, 9b and 10 (Figure 8.4a). This molecular design was expected to form planar perylene cores that can strongly interact by pi-pi stacking and H-bonding. POM, DSC and X-ray investigations of the compounds suggest lamellar LC phases for PBIs 9a and 9b and a soft phase for PBI 10. In this regard, the goal of the formation of LC lamellar phase of PBIs could be attained. The change from dendrons with n-C12-alkoxy chains to large fork-like mesogens like in 9b clearly changed the phase properties. PBI 9b exhibits the lowest clearing point, high phase stability, least viscosity, easy shearability at room temperature and phase transitions between lamellar and Colh phases dependent on temperature. The formation of H-bonds parallel to the layers was demonstrated by polarized FT-IR experiments for all three PBIs. Concentration-dependent UV-Vis absorption studies revealed the formation of a J-type aggregate, which seems to exhibit an overall two-dimensional structure. With STM investigations the formation of lamellar structures from drop-casted 9a and 10 solutions in 1-phenyloctane on HOPG surface could be observed. Figure 8.4b illustrates a schematic possible arrangement of the molecules in the layers (here exemplarily demonstrated for PBI 9a), which has to be further confirmed by modelling and simulations. Unfortunately, fluorescence investigations of the thin films revealed non- or only slightly emissive LC states, which make them negligible for photonic applications. Nevertheless, the synthesized and analyzed compounds might be an inspiration for further investigations on the path to two-dimensional exciton transport for photonic devices.},
  subject      = {Fl{\"u}ssigkristall},
  language  = {en}
}
@phdthesis{Muzha2022,
  author    = {Muzha, Andreas},
  title     = {Herstellung und Charakterisierung kolloidaler L{\"o}sungen diamantbasierter und verwandter Materialien},
  doi       = {10.25972/OPUS-29668},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-296685},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In der vorliegenden Publikation wurden stabile kolloidale L{\"o}sungen aus CVD-Diamant, Detonationsdiamant sowie artverwandten Materialien hergestellt und charakterisiert Besonderes Augenmerk wurde bei der Zerkleinerung von CVD Diamant daraufgelegt, dass die nanoskaligen Partikel ihre materialspezifischen Eigenschaften auch bei Reduktion der Gr{\"o}ße beibehalten. Systematisch wurde die Zerkleinerung in einer Planetenm{\"u}hle analysiert. Es wurde sowohl die minimal erreichbare Partikelgr{\"o}ße, als auch die Menge an erzeugtem, nanoskaligem Material bewertet. Um die Vermahlung zu verbessern, wurden die Geschwindigkeit der M{\"u}hle, die Gr{\"o}ße der Mahlk{\"o}rper, die Dauer der Vermahlung, sowie die eingesetzten L{\"o}semittel variiert. Des Weiteren konnten durch die Vermahlung unterschiedlich hergestellter CVD Diamantfilme in einer Vibrationsm{\"u}hle die Einfl{\"u}sse von Schichtdicke und Korngr{\"o}ße der Diamantkristalle untersucht werden. Durch Bearbeitung von Detonationsdiamanten und Kohlenstoffnanozwiebeln wurden stabile kolloidale L{\"o}sungen hergestellt, mit Partikelgr{\"o}ßen im unteren Nanometerbereich. Diese sind im alkalischen pH-Bereich stabil sein, hierf{\"u}r wurde durch Luft und S{\"a}ureoxidation oxidierter Detonationsdiamant und oxidierte Kohlenstoffnanozwiebeln hergestellt. Mithilfe der thermogravimetrischen Analyse und Infrarotspektroskopie wurde die hierf{\"u}r optimale Temperatur und Dauer bestimmt.},
  subject      = {Diamant},
  language  = {de}
}
@phdthesis{GamachegebRupp2021,
  author    = {Gamache [geb. Rupp], Mira Theresa},
  title     = {Ligand Design for Ru(II) Photosensitizers in Photocatalytic Hydrogen Evolution},
  doi       = {10.25972/OPUS-24676},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246766},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {This thesis investigates different ligand designs for Ru(II) complexes and the activity of the complexes as photosensitizer (PS) in photocatalytic hydrogen evolution. The catalytic system typically contains a catalyst, a sacrificial electron donor (SED) and a PS, which needs to exhibit strong absorption and luminescence, as well as reversible redox behavior. Electron-withdrawing pyridine substituents on the terpyridine metal ion receptor result in an increase of excited-state lifetime and quantum yield (Φ = 74*10-5; τ = 3.8 ns) and lead to complex III-C1 exhibiting activity as PS. While the turn-over frequency (TOFmax) and turn-over number (TON) are relatively low (TOFmax = 57 mmolH2 molPS-1 min-1; TON(44 h) = 134 mmolH2 molPS-1), the catalytic system is long-lived, losing only 20\% of its activity over the course of 12 days. Interestingly, the heteroleptic design in III-C1 proves to be beneficial for the performance as PS, despite III-C1 having comparable photophysical and electrochemical properties as the homoleptic complex IV-C2 (TOFmax = 35 mmolH2 molPS-1 min-1; TON(24 h) = 14 mmolH2 molPS-1). Reductive quenching of the excited PS by the SED is identified as rate-limiting step in both cases. Hence, the ligands are designed to be more electron-accepting either via N-methylation of the peripheral pyridine substituents or introduction of a pyrimidine ring in the metal ion receptor, leading to increased excited-state lifetimes (τ = 9-40 ns) and luminescence quantum yields (Φ = 40-400*10-5). However, the more electron-accepting character of the ligands also results in anodically shifted reduction potentials, leading to a lack of driving force for the electron transfer from the reduced PS to the catalyst. Hence, this electron transfer step is found to be a limiting factor to the overall performance of the PS. While higher TOFmax in hydrogen evolution experiments are observed for pyrimidine-containing PS (TOFmax = 300-715 mmolH2 molPS-1 min-1), the longevity for these systems is reduced with half-life times of 2-6 h. Expansion of the pyrimidine-containing ligands to dinuclear complexes yields a stronger absorptivity (ε = 100-135*103 L mol-1 cm-1), increased luminescence (τ = 90-125 ns, Φ = 210-350*10-5) and can also result in higher TOFmax given sufficient driving force for electron transfer to the catalyst (TOFmax = 1500 mmolH2 molPS-1 min-1). When comparing complexes with similar driving forces, stronger luminescence is reflected in a higher TOFmax. Besides thermodynamic considerations, kinetic effects and electron transfer efficiency are assumed to impact the observed activity in hydrogen evolution. In summary, this work shows that targeted ligand design can make the previously disregarded group of Ru(II) complexes with tridentate ligands attractive candidates for use as PS in photocatalytic hydrogen evolution.},
  subject      = {Fotokatalyse},
  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}
}