@phdthesis{Kerner2021,
  author    = {Kerner, Florian Tobias},
  title     = {Reactions of rhodium(I) with diynes and studies of the photophysical behavior of the luminescent products},
  doi       = {10.25972/OPUS-20910},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-209107},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Chapter 1 deals with the reaction of [Rh(acac)(PMe3)2] with para-substituted 1,4-diphenylbuta-1,3-diynes at room temperature, in which a complex containing a bidentate organic fulvene moiety, composed of two diynes, σ-bound to the rhodium center is formed in an all-carbon [3+2] type cyclization reaction. In addition, a complex containing an organic indene moiety, composed of three diynes, attached to the rhodium center in a bis-σ-manner is formed in a [3+2+3] cyclization process. Reactions at 100 °C reveal that the third diyne inserts between the rhodium center and the bis-σ-bound organic fulvene moiety. Furthermore, the formation of a 2,5- and a 2,4-bis(arylethynyl)rhodacyclopentadiene is observed. The unique [3+2] cyclization product was used for the synthesis of a highly conjugated organic molecule, which is hard to access or even inaccessible by conventional methods. Thus, at elevated temperatures, reaction of the [3+2] product with para-tolyl isocyanate led to the formation of a purple organic compound containing the organic fulvene structure and one equivalent of para-tolyl isocyanate. The blue and green [3+2+3] complexes show an unusually broad absorption from 500 - 1000 nm with extinction coefficients ε of up to 11000 M-1 cm-1. The purple organic molecule shows an absorption spectrum similar to those of known diketopyrrolopyrroles. Additionally, the reaction of [Rh(acac)(PMe3)2] with para-tolyl isocyanate was investigated. A cis-phosphine complex of the form cis-[Rh(acac)(PMe3)2(isocyanate)2] with an isocyanate dimer bound to the rhodium center by one carbon and one oxygen atom was isolated. Replacing the trimethylphosphine ligands in [Rh(acac)(PMe3)2] with the stronger σ-donating NHC ligand Me2Im (1,3-dimethylimidazolin-2-ylidene), again, drastically alters the reaction. Similar [3+2] and [3+2+3] products to those discussed above could not be unambiguously assigned, but cis- and trans-π-complexes, which are in an equilibrium with the two starting materials, were formed. Chapters 2 is about the influence of the backbone of the α,ω-diynes on the formation and photophysical properties of 2,5-bis(aryl)rhodacyclopentadienes. Therefore, different α,ω-diynes were reacted with [Rh(acac)(PMe3)2] and [Rh(acac)(P(p-tolyl)3)2] in equimolar amounts. In general, a faster consumption of the rhodium(I) starting material is observed while using preorganized α,ω-diynes with electron withdrawing substituents in the backbone. The isolated PMe3-substituted rhodacyclopentadienes exhibit fluorescence, despite the presence of the heavy atom rhodium, with lifetimes τF of < 1 ns and photoluminescence quantum yields Φ of < 0.01 as in previously reported P(p-tolyl)-substituted 2,5-bis(arylethynyl)rhodacyclopentadienes. However, an isolated P(p-tolyl)-substituted 2,5-bis(aryl)rhodacyclopentadiene shows multiple lifetimes and different absorption and excitation spectra leading to the conclusion that different species may be present. Reaction of [Rh(acac)(Me2Im)2] with dimethyl 4,4'-(naphthalene-1,8-diylbis(ethyne-2,1-diyl))dibenzoate, results in the formation of a mixture trans- and cis-NHC-substituted 2,5-bis(aryl)rhodacyclopentadienes. In chapter 3 the reaction of various acac- and diethyldithiocarbamate-substituted rhodium(I) catalysts bearing (chelating)phosphines with α,ω-bis(arylethynyl)alkanes (α,ω-diynes), yielding luminescent dimers and trimers, is described. The photophysical properties of dimers and trimers of the α,ω-diynes were investigated and compared to para-terphenyl, showing a lower quantum yield and a larger apparent Stokes shift. Furthermore, a bimetallic rhodium(I) complex of the form [Rh2(ox)(P(p-tolyl)3)4] (ox: oxalate) was reacted with a CO2Me-substituted α,ω-tetrayne forming a complex in which only one rhodium(I) center reacts with the α,ω-tetrayne. The photophysical properties of this mixed rhodium(I)/(III) species shows only negligible differences compared to the P(p-tolyl)- and CO2Me-substituted 2,5-bis(arylethynyl)rhodacyclopentadiene, previously synthesized by Marder and co-workers.},
  subject      = {{\"U}bergangsmetallkomplexe},
  language  = {en}
}
@phdthesis{Eck2018,
  author    = {Eck, Martin},
  title     = {Iron- and Copper-catalyzed Borylation of Alkyl and Aryl Halides and B-B Bond Activation and NHC Ring-expansion Reactions of the Diboron(4) Compound Bis(ethylene glycolato)diboron (B\(_2\)eg\(_2\))},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149791},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {The purpose of the present work was, in the first part, to investigate the potential of iron-based metal complexes in catalytic borylation reactions with alkyl halides as substrates and B2pin2 as the borylation reagent. Moreover, extended studies of the recently reported, copper mediated borylation reactions of aryl halides were performed, including the screening of substrates and alkoxy bases as well as ligand-screening. Investigations were undertaken on the role of Cu-nanoparticles, which might be involved in this catalytic reaction. Furthermore, Cu-phosphine complexes were synthesized as precursors, but attempts to isolate Cu-boryl species which are intermediates in the proposed catalytic cycle were unsuccessful, although 11B NMR evidence for a Cu-boryl complex was obtained. In the second part of this work, the alternative, Lewis-acidic diboron(4) compound bis(ethylene glycolato)diboron (B2eg2) was synthesized to compare its reactivity with the reactivity of other diboron(4) compounds (e.g. B2neop2, B2cat2, B2pin2 and B2(NMe2)4). Therefore, reactions of B2eg2 with different Lewis-bases, such as NHCs and phosphines, were performed to investigate the possible formation of sp2-sp3 or sp3-sp3 adducts and ring-expansion reactions (RERs). The aim was to obtain a better general insight into the reactivity of diboron(4) compounds with Lewis-bases because they are both used as reactants in transition metal-catalyzed and metal-free borylation reactions. Understanding the B-B bond activation process promoted by Lewis-bases provides a new perspective on the reaction pathways available for various borylation reactions.},
  language  = {en}
}
@phdthesis{Hailmann2018,
  author    = {Hailmann, Michael},
  title     = {Carba-closo-dodecaboranylethinyl-Liganden und deren Einsatz als Liganden f{\"u}r M{\"u}nzmetall(I)-Komplexe},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-149249},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Ein wesentliches Ziel dieser Arbeit war die Synthese von mehrfach funktionalisierten Carba-closo-dodecaborat-Anionen, um lineare Bausteine f{\"u}r h{\"o}hermolekulare Netzwerke zu generieren. Speziell funktionelle Gruppen, die entweder zwei Koordinationstellen aufweisen oder weitere Funktionalisierungen erm{\"o}glichen, stehen im Fokus. Des Weiteren soll die Koordinationschemie von Carba-closo-dodecaborat-Anionen mit Ethinylgruppen am antipodalen Boratom, besonders in Hinsicht auf die Bildung von M{\"u}nzmetall(I)-Komplexen untersucht werden. Im Rahmen dieser Themengebiete wurden zahlreiche zweifach funktionalisierte Derivate des Carba-closo-dodecaboratanions synthetisiert. Drei ausgew{\"a}hlte Anionen sind in Abbildung 141 gezeigt. {\"U}berdies wurde mit der Synthese von [1-H2CHCC(O)NH-closo-1-CB11H11]- gezeigt, dass die Aminofunktion derivatisiert werden kann. Diese Resultate erm{\"o}glichen die Synthese einer breiten Palette an linearen Bausteinen, beispielsweise f{\"u}r die Verwendung als Linker in h{\"o}hermolekularen Netzwerken.Zudem wurden Bausteine synthetisiert, welche {\"u}ber Wasserstoffbr{\"u}cken-bindungen lineare Str{\"a}nge bilden . Aufgrund des, f{\"u}r Carboxylgruppen selten beobachteten Motivs von tetrameren Einheiten mit dem Graph-Set-Deskriptor [R44(16)] sticht die Struktur von [1-HO(O)C-12-HCC-closo-1-CB11H10]- besonders hervor, da normalerweise f{\"u}r Carbons{\"a}uren die Bildung von Dimeren bevorzugt ist.[129-131] Die maximale L{\"a}nge des tetrameren, cyclischen Bausteins betr{\"a}gt 2.24 nm. Das Anion [1-H2N(O)C-12-HCC-closo-1-CB11H10]- bildet einen linearen Strang mit einer L{\"a}nge von 2.10 nm, welcher an beiden Enden funktionelle Gruppen tr{\"a}gt. Ein interessantes Einsatzgebiet von derartigen Verbindungen ist wiederum die Verwendung als Liganden im Bereich von M{\"u}nzmetall(I)-Komplexen, wie sie beispielsweise von Himmelspach et al.[87] synthetisiert wurden, wobei in diesem Fall {\"u}ber das Wasserstoffbr{\"u}ckenbindungsmotiv ein Verkn{\"u}pfungspunkt vorhanden w{\"a}re, um h{\"o}hermolekulare Netzwerke zu bilden. Des Weiteren wurde der elektronische Einfluss verschiedener funktioneller Gruppen auf die Polarisierung der Alkinylfunktion {\"u}ber das {closo-CB11}-Ger{\"u}st untersucht. Die Differenzen der experimentellen und berechneten chemischen Verschiebungen der Alkinylresonanzen stehen in linearem Zusammenhang mit der berechneten Differenz der NBO-Ladung des entsprechenden Clusters, wie Abbildung 143 zu entnehmen ist. Im Vergleich mit in 1,4-Position substituierten Derivaten von Benzol und Bicyclo[2.2.2]oktan wird deutlich, dass bei dem Carba-closo-dodecaborat-Anion in gr{\"o}ßerem Maße induktive Effekte eine Rolle spielen, aber zu einem gewissen Teil auch mesomere Effekte {\"u}ber das {closo-1-CB11}-Ger{\"u}st vermittelt werden. Dementsprechend ist das Carba-closo-dodecaborat-Anion zwischen den beiden Extremf{\"a}llen Benzol - mit dominierenden mesomeren Effekten - und Bicyclo[2.2.2]oktan - mit reinen induktiven Effekten - einzuordnen.Durch die Verwendung ausgew{\"a}hlter funktionalisierter Pyridinderivate wurde ein breites Spektrum unterschiedlicher AgI-Cluster synthetisiert. Mit Pyridin und 4-Me-Pyridin ist die Struktur im Festk{\"o}rper ein Oktaeder. Bei Verwendung von 4 tBu-Pyridin wird neben eines, auf einer Seite ge{\"o}ffneten Oktaeders, auch ein stark verzerrtes geschlossenes Oktaeder beobachtet. Wird 4-F3C-Pyridin als Ligand verwendet, werden je nach Reaktionstemperatur zwei verschiedene geometrische Grundger{\"u}ste im Festk{\"o}rper erhalten. Bei Temperaturen {\"u}ber 20 °C wird ein Oktaeder und bei Temperaturen unter 15 °C ein Dekaeder aus AgI-Ionen im Festk{\"o}rper gebildet. Bei Einsatz von 3,5-Me-Lutidin hingegen formt sich eine pentagonale Bipyramide.Diese Komplexe phosphoreszieren bei Raumtemperatur, was f{\"u}r diese Verbindungsklasse sehr selten beobachtet wird. Des Weiteren konnten Informationen hinsichtlich der Struktur-Eigenschafts-Beziehung solcher Komplexe erhalten werden, so wird die Quantenausbeute der einzelnen Komplexe maßgeblich von der Struktur beeinflusst wird. W{\"a}hrend das am h{\"a}ufigsten beobachtete geometrische Grundger{\"u}st das Oktaeder ist und die Quantenausbeuten f{\"u}r diese Serie von Clustern in einem Bereich zwischen 0.01 und 0.14 liegen, wird bei Verwendung von 3,5-Me2-Lutidin als Ligand eine pentagonale Bipyramide gebildet, die sich dar{\"u}ber hinaus mit einer Quantenausbeute von 0.76 deutlich von allen anderen bislang synthetisierten Komplexen hervorhebt. Mit den eben erw{\"a}hnten Silber(I)-Komplexen wurden Ergebnisse bei Umsetzungen mit halogenidhaltigen Salzen erhalten. Auch hier wurden Unterschiede bei den verschiedenen Liganden beobachtet und bei Verwendung von 3,5-Me2-Lutidin wurden, in Abh{\"a}ngigkeit der verwendeten Kationen der eingesetzten Halogenid-Salze, unterschiedliche Komplexe erhalten. Im Falle des [Et4N]+-Kations bleibt die pentagonale Bipyramide erhalten und [Et4N][Ag7(12-CC-closo-1-CB11H11)4(3,5-Me2-C5H3N)9] bildet sich, w{\"a}hrend bei Verwendung des [Ph4P]+-Kations [Ph4P][Ag7(12-CC-closo-1-CB11H11)4(3,5-(Me)2C5H3N)13] erhalten wird und die Struktur im Kristall ist mit der von [Ag(C5H5N)4][(Ag7(12-CC-closo-1-CB11H11)4(C5H5N)11] verwandt. Die Struktur-Eigenschaft-Beziehung der Komplexe wird hierbei best{\"a}tigt, da f{\"u}r beide Komplexe sehr unterschiedliche Quantenausbeuten gemessen werden. Der Cluster mit dem pentagonal bipyramidalen Aufbau [Et4N][Ag7(12-CC-closo-1-CB11H11)4(3,5-Me2-C5H3N)8] hat eine Quantenausbeute von 0.23 gemessen, w{\"a}hrend die Quantenausbeute im Fall von [Ph4P][Ag7(12-CC-closo-1-CB11H11)4(3,5-(Me)2C5H3N)13] nur 0.04 betr{\"a}gt. Dies belegt, dass die Struktur des AgI-Clusters im Festk{\"o}rper die Lumineszenzeigenschaften maßgeblich bestimmt. Des Weiteren wurden verschiedene M{\"u}nzmetallkomplexe mit Carboranyl-ethinyl- und Triphenylphosphan-Liganden synthetisiert . Auch diese Komplexe lumineszieren bei Bestrahlung mit UV-Licht. Im Falle des gemischten Komplexes {12-(Ph3PAu)((Ph3P)2Ag)]-CC-closo-1-CB11H11} konnte die Quantenausbeute auf 0.39 im Vergleich zu den reinen AgI- und AuI-Verbindungen erh{\"o}ht werden. In diesen F{\"a}llen liegt die Quantenausbeute bei lediglich 0.01 beziehungsweise 0.02.},
  subject      = {Carborane},
  language  = {de}
}
@phdthesis{Lubitz2020,
  author    = {Lubitz, Katharina},
  title     = {Synthese und Untersuchungen zur Reaktivit{\"a}t NHC-stabilisierter Kobaltverbindungen},
  doi       = {10.25972/OPUS-20685},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-206854},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {Die vorliegende Arbeit befasst sich mit der Synthese und den Eigenschaften verschiedener NHC-stabilisierter Kobaltkomplexe. Der Fokus liegt dabei einerseits auf der Entwicklung geeigneter Organokobaltverbindungen, welche sich in CVD bzw. ALD-Prozessen zur Abscheidung von elementarem Kobalt eignen. Hierf{\"u}r wurden verschiedene NHC-stabilisierte sowie gemischt substituierte Kobalt(carbonyl)(nitrosyl)komplexe dargestellt und die thermischen Eigenschaften dieser Verbindungen untersucht. Andererseits wurden Studien zur Synthese und Reaktivit{\"a}t NHC-stabilisierter Halbsandwichverbindungen des Kobalts durchgef{\"u}hrt. Dabei wurde unter anderem {\"u}berpr{\"u}ft, inwiefern sich der sterische Einfluss des NHC-Liganden auf die F{\"a}higkeiten auswirkt, Element-Element-Bindungen in Silanen und Diboranen zu aktivieren. Ferner wurden weitere Untersuchungen zur Reaktivit{\"a}t derartiger Komplexe, insbesondere gegen{\"u}ber Alkinen, vorgenommen. Ein weiterer Teil dieser Arbeit besch{\"a}ftigt sich mit der Darstellung und Reaktivit{\"a}t NHC-Phosphiniden-stabilisierter Kobaltverbindungen.},
  subject      = {Kobalt},
  language  = {de}
}
@phdthesis{Berthel2019,
  author    = {Berthel, Johannes H. J.},
  title     = {Synthese und Charakterisierung neuer NHC-stabilisierter Nickelkomplexe f{\"u}r die Gasphasenabscheidung},
  doi       = {10.25972/OPUS-14757},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-147571},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Die vorliegende Arbeit befasst sich mit der Synthese und Charakterisierung NHC-stabilisierter Nickelkomplexe, die durch weitere Co-Liganden wie Carbonyle, Olefine, Alkine, Alkyle, Cyanide oder Allylliganden koordiniert sind. Ferner gibt diese Arbeit einen {\"U}berblick {\"u}ber die thermischen Eigenschaften dieser Verbindungen, um deren Potenzial f{\"u}r den Einsatz zur Abscheidung elementaren Nickels in CVD- bzw. ALD-Prozessen absch{\"a}tzen zu k{\"o}nnen. Dabei konnten vor allem die Substanzklassen der Carbonyl- und Alkylkomplexe als geeignete Pr{\"a}kursoren f{\"u}r die Gasphasenabscheidung elementaren Nickels identifiziert werden, von denen einige ausgew{\"a}hlte Vertreter bereits erfolgreich in CVD-Prozessen getestet wurden.},
  subject      = {Nickelkomplexe},
  language  = {de}
}
@phdthesis{Hock2021,
  author    = {Hock, Andreas},
  title     = {NHC-stabilized Alanes and Gallanes},
  doi       = {10.25972/OPUS-21252},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212525},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {This thesis describes the synthesis and reactivity of NHC-stabilized Lewis-acid/Lewis-base adducts of alanes and gallanes (NHC = Me2ImMe, iPr2Im, iPr2ImMe, Dipp2Im, Dipp2ImH). As this field of research has developed tremendously, especially in the last five years, the first chapter provides an overview of the current state of knowledge. The influence of electronegative π-donor-substituents on the stability of the NHC alane adducts is examined in chapter 2. For this purpose, the carbene stabilized alanes (NHC)∙AlH3 (NHC = iPr2Im, Dipp2Im) were reacted with secondary amines of different steric demand and with phenols. The π-donor substituents saturate the Lewis acidic aluminium center and coordination of a second NHC-ligand was not observed. The strongly electronegative N and O substituents increase the Lewis acidity of the aluminium atom, which leads to stronger Al-CNHC as well as Al-H bonds, which inhibits the insertion of the carbene into the Al-H bond. In Chapter 3 the development of the synthesis and reactivity of carbene-stabilized gallanes is presented. The synthesis of NHC gallane adducts (NHC)∙GaH3, (NHC)∙GaH2Cl and (NHC)∙GaHCl2 and their reactivity towards NHCs and cAACMe were investigated in detail. The reaction of the mono- and dichlorogallanes (NHC)∙GaH2Cl and (NHC)∙GaHCl2 (NHC = iPr2ImMe, Dipp2Im) with cAACMe led to insertion of the cAACMe with formation of chiral and achiral compounds depending on the sterically demand of the used NHC. Furthermore, the formation of bis-alkylgallanes was observed for the insertion of two equivalents of cAACMe with release of the NHC ligand. Chapter 4 describes investigations concerning the synthesis and reactivity of NHC-stabilized iodoalanes and iodogallanes, which are suitable for the formation of cationic aluminium and gallium dihydrides. The reaction of (NHC)∙EH2I (E = Al, Ga) stabilized by the sterically less demanding NHCs (NHC = Me2ImMe, iPr2Im, iPr2ImMe) with an additional equivalent of the NHC led to the formation of the cationic bis-NHC aluminium and gallium dihydrides [(NHC)2∙AlH2]+I- and [(NHC)2∙GaH2]+I-. Furthermore, the influence of the steric demand of the used NHC was investigated. The adduct (Dipp2Im)∙GaH2I was reacted with an additional equivalent of Dipp2Im. Due to the bulk of the NHC used, rearrangement of one of the NHC ligands from normal to abnormal coordination occurred and the cationic gallium dihydride [(Dipp2Im)∙GaH2(aDipp2Im)] was isolated. Chapter 5 of this thesis reports investigations concerning the reduction of cyclopentadienyl-substituted alanes and gallanes with singlet carbenes. NHC stabilized pentamethylcyclopentadienyl aluminium and gallium dihydrides (NHC)∙Cp*MH2 (E = Al, Ga) were prepared by the reaction of (AlH2Cp*)3 with the corresponding NHCs or by the salt elimination of (NHC)∙GaH2I with KCp*. The gallane adducts decompose at higher temperatures with reductive elimination of Cp*H and formation of Cp*GaI. . The reductive elimination is preferred for sterically demanding NHCs (Dipp2Im > iPr2ImMe > Me2ImMe). In addition, NHC ring expansion of the backbone saturated carbene Dipp2ImH was observed for the reaction of the NHC with (AlH2Cp*)3, which led to (RER-Dipp2ImHH2)AlCp*. Furthermore, the reactivity of the adducts (NHC)∙Cp*EH2 (E = Al, Ga) towards cAACMe was investigated. The reaction of the alane adducts stabilized by the sterically more demanding NHCs iPr2ImMe and Dipp2Im afforded the exceptionally stable insertion product (cAACMeH)Cp*AlH V-10 with liberation of the NHC. The reaction of the gallium hydrides (NHC)∙Cp*GaH2 with cAACMe led to the reductive elimination of cAACMeH2 and formation of Cp*GaI. A variety of neutral and cationic carbene-stabilized alanes and gallanes are presented in this work. The introduction of electronegative π-donor substituents (Cl-, I-, OR-, NR2-) and the investigations on the thermal stability of these compounds led to the conclusion that the stability of alanes and gallanes increased significantly by such a substitution. Investigations on the reactivity of the NHC adducts towards cAACMe resulted in various insertion products of the carbene into the Al-H or Ga-H bonds and the first cAACMe stabilized dichlorogallane was isolated. Furthermore, a first proof was provided that carbenes can be used specifically for the (formal) reduction of group 13 hydrides of the higher homologues. Thus, the synthesis of Cp*GaI from the reaction of (NHC)∙Cp*GaH2 with cAACMe was developed. In the future, this reaction pathway could be of interest for the preparation of other low-valent compounds of aluminium and gallium.},
  subject      = {Aluminiumhydridderivate},
  language  = {en}
}
@phdthesis{Schulze2016,
  author    = {Schulze, Marcus},
  title     = {Ruthenium Complexes as Water Oxidation Catalysts and Photosensitizers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142454},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {In der vorliegenden Arbeit werden Aspekte der photokatalytischen Wasseroxidationsreaktion behandelt. Der erste Themenschwerpunkt der Dissertation besch{\"a}ftigt sich mit einem supramolekularen Makrozyklus, der drei Rutheniummetallzentren enth{\"a}lt. Dieser neuartige Katalysator zeigt eine sehr hohe katalytische Aktivit{\"a}t und gew{\"a}hrt neue Einblicke in den Mechanismus der Wasseroxidationsreaktion. Des Weiteren wird auf die mit Licht interagierenden Komponenten der photokatalytischen Wasseroxidation eingegangen. Hierbei haben sich azabenz-anellierte Perylenderivate als vielseitige Farbstoffklasse herausgestellt. Die Kombination dieser Farbstoffe mit Metallkomplexen liefert metallorganische Verbindungen, die als Photosensibilisatoren eingesetzt werden k{\"o}nnen.},
  subject      = {Farbstoff},
  language  = {en}
}
@phdthesis{Seufert2019,
  author    = {Seufert, Jens},
  title     = {Synthese und Reduktionsverhalten neuer Lewis-Basen-Addukte des Bors sowie Redox-aktiver Ligandentransfer durch Silylene},
  doi       = {10.25972/OPUS-17398},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173987},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Im Rahmen dieser Arbeit war es m{\"o}glich, diverse Lewis-Basen f{\"u}r deren Einsatz zur Stabilisierung niedervalenter Borverbindungen zu testen. Dabei wurden neuartige Mono- und Diboran(4)-Addukte mit mesoionischen Carbenen, Phosphanen und Alkyl-verbr{\"u}ckten Carbenen synthetisiert, charakterisiert und deren Reduktionsverhalten getestet. Des Weiteren konnte gezeigt werden, dass elektronenreiche Bis(amidinato)- und Bis(guanidinato)silylene eine diverse Vielfalt an Reaktionstypen induzieren und dabei zu Redox-Reaktionen und Liganden{\"u}bertrag neigen.},
  subject      = {Bor},
  language  = {de}
}
@phdthesis{Kunz2018,
  author    = {Kunz, Valentin},
  title     = {Supramolecular Approaches for Water Oxidation Catalysis with Ruthenium Complexes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-154820},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {The catalytic splitting of water into its elements is an important reaction to establish hydrogen as a solar fuel. The bottle-neck of this process is considered to be the oxidative half reaction generating oxygen, and good catalysts are required to handle the complicated redox chemistry involved. As can be learned from nature, the incorporation of the catalytically active species into an appropriate matrix can help to improve the overall performance. Thus, the aim of the present thesis was to establish novel supramolecular approaches to improve water oxidation catalysis using the catalytically active {Ru(bda)} fragment as key motive (bda = 2,2'-bipyridine-6,6'-dicarboxylate). First, the synthesis of ruthenium catalysts gathering three {Ru(bda)} water oxidation subunits in a macrocyclic fashion is described. By using bridging bipyridine ligands of different lengths, metallosupramolecular macrocycles with distinct sizes have been obtained. Interestingly, an intermediate ring size has been proven to be optimal for the catalytic water oxidation. Detailed kinetic, spectroscopic, and theoretical studies helped to identify the reaction mechanism and to rationalize the different catalytic activities. Furthermore, solubilizing side chains have been introduced for the most active derivative to achieve full water solubility. Secondly, the {Ru(bda)} fragment was embedded into supramolecular aggregates to generate more stable catalytic systems compared to a homogeneous reference complex. Therefore, the catalyst fragment was equipped with axial perylene bisimide (PBI) ligands, which facilitate self-assembly. Moreover, the influence of the different accessible aggregate morphologies on the catalytic performance has been investigated.},
  subject      = {Ruthenium Komplexe},
  language  = {en}
}
@phdthesis{Tian2021,
  author    = {Tian, Yaming},
  title     = {Selective C-X and C-H Borylation by N-Heterocyclic Carbene Nickel(0) Complex},
  doi       = {10.25972/OPUS-21300},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213004},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Organoboron compounds are important building blocks in organic synthesis, materials science, and drug discovery. The development of practical and convenient ways to synthesize boronate esters attracted significant interest. Photoinduced borylations originated with stoichiometric reactions of arenes and alkanes with well-defined metal-boryl complexes. Now photoredox-initiated borylations, catalyzed either by transition-metal or organic photocatalysts, and photochemical borylations with high efficiency have become a burgeoning area of research. In this chapter, we summarize research in the field of photocatalytic C-X borylation, especially emphasizing recent developments and trends, based on transition-metal catalysis, metal-free organocatalysis and direct photochemical activation. We focus on reaction mechanisms involving single electron transfer (SET), triplet energy transfer (TET), and other radical processes. We developed a highly selective photocatalytic C-F borylation method that employs a rhodium biphenyl complex as a triplet sensitizer and the nickel catalyst [Ni(IMes)2] (IMes = 1,3-dimesitylimidazolin-2-ylidene) for the C-F bond activation and defluoroborylation process. This tandem catalyst system operates with visible (400 nm) light and achieves borylation of a wide range of fluoroarenes with B2pin2 at room temperature in excellent yields and with high selectivity. Direct irradiation of the intermediary C-F bond oxidative addition product trans-[NiF(ArF)(IMes)2] leads to fast decomposition when B2pin2 is present. This destructive pathway can be bypassed by indirect excitation of the triplet states of the nickel(II) complex via the photoexcited rhodium biphenyl complex. Mechanistic studies suggest that the exceptionally long-lived triplet excited state of the Rh biphenyl complex used as the photosensitizer allows for efficient triplet energy transfer to trans-[NiF(ArF)(IMes)2], which leads to dissociation of one of the NHC ligands. This contrasts with the majority of current photocatalytic transformations, which employ transition metals as excited state single electron transfer agents. We have previously reported that C(arene)-F bond activation with [Ni(IMes)2] is facile at room temperature, but that the transmetalation step with B2pin2 is associated with a high energy barrier. Thus, this triplet energy transfer ultimately leads to a greatly enhanced rate constant for the transmetalation step and thus for the whole borylation process. While addition of a fluoride source such as CsF enhances the yield, it is not absolutely required. We attribute this yield-enhancing effect to (i) formation of an anionic adduct of B2pin2, i.e. FB2pin2-, as an efficient, much more nucleophilic {Bpin-} transfer reagent for the borylation/transmetalation process, and/or (ii) trapping of the Lewis acidic side product FBpin by formation of [F2Bpin]- to avoid the formation of a significant amount of NHC-FBpin and consequently of decomposition of {Ni(NHC)2} species in the reaction mixture. We reported a highly selective and general photo-induced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes. This photo-induced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]•- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle. A highly efficient and general protocol for traceless, directed C3-selective C-H borylation of indoles with [Ni(IMes)2] as the catalyst was achieved. Activation and borylation of N-H bonds by [Ni(IMes)2] is essential to install a Bpin moiety at the N-position as a traceless directing group, which enables the C3-selective borylation of C-H bonds. The N-Bpin group which is formed is easily converted in situ back to an N-H group by the oxidiative addition product of [Ni(IMes)2] and in situ-generated HBpin. The catalytic reactions are operationally simple, allowing borylation of of a variety of substituted indoles with B2pin2 in excellent yields and with high selectivity. The C-H borylation can be followed by Suzuki-Miyaura cross-coupling of the C-borylated indoles in an overall two-step, one-pot process providing an efficient method for synthesizing C3-functionalized heteroarenes.},
  subject      = {Borylierung},
  language  = {en}
}
@phdthesis{Konieczka2017,
  author    = {Konieczka, Szymon Zbigniew},
  title     = {Untersuchungen zu neuen polyhalogenierten Aminocarba-\(closo\)-dodecaboraten},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122548},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Die Arbeit umfasst zum einen Untersuchungen zu hochhalogenierten 1-Aminocarba-closo-dodecaboraten, zum anderen Untersuchungen zu hochfluorierten Aminocarba-closo-dodecaboraten mit einer an ein Boratom gebundenen Amino-Funktion. Außerdem wurden im diesem Zuge closo-Undecaborat-Cluster untersucht, da diese als interessante Ausgangsverbindungen f{\"u}r funktionalisierte {CB11}-Derivate eingesetzt werden k{\"o}nnen.},
  subject      = {carborane},
  language  = {de}
}
@phdthesis{Brand2015,
  author    = {Brand, Johannes},
  title     = {Darstellung und Untersuchung von niederkoordinierten Platinimino-, Platinoxo- und Platinalkylidenborylkomplexen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112306},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Diese Dissertation handelt von der Darstellung, Charakterisierung und Reaktivit{\"a}tsuntersuchungen von neuartigen Platinalkylidenborylkomplexen und eines heteroleptischen Platiniminoborylkomplexes. Außerdem wurden Reaktivit{\"a}tsuntersuchungen an einem Platinoxoborylkomplex durchgef{\"u}hrt und die erhaltenen Produkte wurden genau untersucht und charakterisiert.},
  subject      = {Dreifachbindung},
  language  = {de}
}
@phdthesis{Geyer2015,
  author    = {Geyer, Marcel},
  title     = {Synthese und biologische Charakterisierung neuartiger siliciumorganischer Wirkstoffe sowie Synthese neuartiger siliciumorgansicher Synthese-Bausteine},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123766},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Aufbauend auf dem Konzept der C/Si-Bioisosterie beschreibt die vorliegende Arbeit die Synthese und biologische Charakterisierung siliciumorganischer Wirkstoffe sowie Beitr{\"a}ge zur Synthese von siliciumorganischen Synthese-Bausteinen unter Verwendung der Silicium-Schutzgruppen MOP (4-Methoxyphenyl), DMOP (2,6-Dimethoxyphenyl) und TMOP (2,4,6-Trimethoxyphenyl). Die entsprechenden Zielverbindungen sowie alle isolierten Zwischenstufen wurden durch NMR-Spektroskopie in L{\"o}sung (1H, 13C, 29Si) und Elementaranalyse (C, H, N) bzw. HRMS-Analytik (ESI) charakterisiert. Zus{\"a}tzlich konnte in einigen F{\"a}llen eine strukturelle Charakterisierung durch Einkristall-R{\"o}ntgenstrukturanalyse realisiert werden.},
  subject      = {Wirkstoff},
  language  = {de}
}
@phdthesis{Liu2021,
  author    = {Liu, Zhiqiang},
  title     = {Fluorinated Aryl Boronates as Units in Organic Synthesis},
  doi       = {10.25972/OPUS-24576},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-245769},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {It is generally acknowledged that polyfluoroarenes are important fluorinated structural units for various organic molecules, such as pharmaceuticals, agrochemicals, and organic materials. Polyfluorinated aryl alkynes and alcohols are also powerful building blocks in chemical synthesis because of their versatility to be transformed into various useful molecules and also their ubiquity in natural product synthesis. Efficient methods for the synthesis of polyfluorinated aryl alkynes and alcohols are presented in Chapter 2 and Chapter 3. In addition, 3-amino-indoles have found a broad applications in medicinal chemistry as effective anticancer agents, compounds with analgesic properties and can function as potent inhibitors of tubulin polymerization, and agents for the prevention of type II diabetes. A simple method for the synthesis of 3-amino-indoles via the annulation reaction of polyfluorophenylboronates with DMF is reported in Chapter 4. Chapter 2 In Chapter 2, a mild process for the copper-catalyzed oxidative cross-coupling of electron-deficient polyfluorophenylboronate esters with terminal alkynes (Scheme S-1) is reported. This method displays good functional group tolerance and broad substrate scope, generating cross-coupled alkynyl(fluoro)arene products in moderate to excellent yields. This copper-catalyzed reaction was conducted on a gram scale to generate the corresponding product in good yield (72\%). Scheme S-1. Copper-catalyzed oxidative cross-coupling of terminal alkynes with polyfluorophenylboronate esters. Based on previous reports and the aforementioned observations, a plausible catalytic cycle for this oxidative cross-coupling reaction is shown in Scheme S-2. The first step involves the addition of an alkynyl anion to Cu leading to the formation of alkynylcopper(II) species B. Subsequent transmetalation between ArFBpin and intermediate B occurs to form intermediate C. The desired product 3a is generated by eductive elimination. Finally, the oxidation of Cu(0) to Cu(II) with DDQ and Ag2O regenerates A to complete the catalytic cycle. Scheme S-2. Proposed mechanism of copper(II)-catalyzed oxidative cross-coupling between terminal alkynes and polyfluorophenylboronate esters. Chapter 3 In Chapter 3, A convenient and efficient protocol for the transition metal-free 1,2-addition of polyfluoroaryl boronate esters to aldehydes and ketones is reported, which provides secondary alcohols, tertiary alcohols, and ketones (Scheme S-3). The distinguishing features of this procedure include the employment of commercially available starting materials and the broad scope of the reaction with a wide variety of carbonyl compounds giving moderate to excellent yields. Scheme S-3. Base-promoted 1,2-addition of polyfluorophenylboronates to aldehydes and ketones. Control experiments were carried out to gain insight into the reaction mechanism. The reaction of 2a with pentafluorobenzene 5 under standard conditions was examined, yet 3a was not formed in any detectable amounts (Scheme S-4a), indicating that the C-Bpin moiety is essential and deprotonation of the fluoroarene or nucleophilic attack at the fluoroarene by the base is not a plausible pathway. Interestingly, for the standard reaction between 1a and 2a, the yield dropped dramatically if 18-crown-6 ether and K2CO3 were added (Scheme S-4b). This experimental result indicates that the presence of the potassium ion plays a crucial role for the outcome of the reaction. Furthermore, if the reaction of 1a and 2a was performed in the presence of only a catalytic amount of K2CO3 (20 mol\%) (Scheme S-4c), reaction rates were reduced, and a week was required to produce 3a in good yield. This finding again indicates that the potassium ion (or the base) plays an important role in the reaction. Substituting ortho-fluorines by ortho-chlorines, using either C6Cl5Bpin 2,6-dichlorophenyl-1-Bpin as substrates, did not yield any product as shown by in situ GCMS studies. Scheme S-4. Control experiments. Based on DFT calculations, a mechanism for the 1,2-addition of polyfluorophenylboronates to aryl aldehydes in the presence of K2CO3 as base is proposed, as shown in Scheme S-5. K2CO3 interacts with the Lewis-acidic Bpin moiety of substrate 1 to generate base adduct A, which weakens the carbon-boron bond and ultimately cleaves the BC bond along with attachment of a potassium cation to the aryl group. The resulting ArF- anion adduct B undergoes nucleophilic attack at the aldehyde carbon atom of substrate 2 to generate methanolate C. The methanolate oxygen atom then attacks the electrophilic Bpin group to obtain compound D. Transfer of K2CO3 from intermediate D to the boron atom of the more Lewis-acidic polyfluorophenyl-Bpin 1 finally closes the cycle and regenerates complex A. Thus, the primary reaction product is the O-borylated addition product E, which was detected by HRMS and NMR spectroscopy for the perfluorinated derivative. Scheme S-5. Proposed mechanism of the 1,2-addition of polyfluorophenylboronates to aldehydes and ketones. Chapter 4 Chapter 4 presents a novel protocol for the transition metal-free addition and annulation of polyfluoroarylboronate esters to DMF, which provides 3-aminoindoles and tertiary amines in moderate to excellent yields (Scheme S-6). Scheme S-6. Annulation and addition reactions of polyfluorophenylboronates with DMF. While exploring the application of this strategy in synthesis, perfluorophenylBpin reacted smoothly with ethynylarenes and DMF to afford propargylamines with moderate to excellent yields (Scheme S-7). Scheme S-7. Three-component cross-coupling reaction for the synthesis of propargylamines.},
  subject      = {Fluorinated Aryl Boronates},
  language  = {en}
}
@phdthesis{WuertembergerPietsch2017,
  author    = {W{\"u}rtemberger-Pietsch, Sabrina},
  title     = {Anionic and Neutral Lewis-Base Adducts of Diboron(4) Compounds},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-136321},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Anionic Adducts Sp2-sp3 tetraalkoxy diboron compounds have gained attention due to the development of new, synthetically useful catalytic reactions either with or without transition-metals. Lewis-base adducts of the diboron(4) compounds were suggested as possible intermediates in Cu catalyzed borylation reactions some time ago. However, intermolecular adducts of tetraalkoxy diboron compounds have not been studied yet in great detail. In preliminary studies, we have synthesized a series of anionic sp2-sp3 adducts of B2pin2 with alkoxy-groups (L = [OMe]-, [OtBu]-), a phenoxy-group (L = [4-tBuC6H4O]-) and fluoride (L = [F]-, with [nBu4N]+ as the counter ion) as Lewis-bases. Neutral Adducts Since their isolation and characterization, applications of N-heterocyclic carbenes (NHCs) and related molecules, e.g., cyclic alkylaminocarbenes (CAACs) and acyclic diaminocarbenes (aDCs), have grown rapidly. Their use as ligands in homogeneous catalysis and directly in organocatalysis, including recently developed borylation reactions, is now well established. Recently, several examples of ring expansion reactions (RER) involving NHCs were reported to take place at elevated temperatures, involving Be, B, and Si. Furthermore, preliminary studies in the group of Marder et al. showed the presence of neutral sp2-sp3 diboron compounds with B2pin2 and the NHC Cy2Im. In this work, we focused on the synthesis and characterization of further neutral sp2-sp3 as well as sp3-sp3 diboron adducts with B2cat2 and B2neop2 and different NHCs. Whereas the mono-NHC adduct is stable for several hours at temperatures up to 60 °C, the bis-NHC adducts undergo thermally induced rearrangement to form the ring expanded products compound 26 and 27. B2neop2 is much more reactive than B2cat2 giving ring expanded product 29 at room temperature in quantitative yields, demonstrating that NHC ring expansion and B-B bond cleavage can be very facile processes. Whereas the mono-NHC adduct is stable for several hours at temperatures up to 60 °C, the bis-NHC adducts undergo thermally induced rearrangement to form the ring expanded products compound 26 and 27. B2neop2 is much more reactive than B2cat2 giving ring expanded product 29 at room temperature in quantitative yields, demonstrating that NHC ring expansion and B-B bond cleavage can be very facile processes.},
  subject      = {Addukt},
  language  = {en}
}
@phdthesis{Hering2014,
  author    = {Hering, Florian},
  title     = {Sterische und elektronische Stabilisierung niedervalenter {\"U}bergangsmetallverbindungen durch N-heterocyclische Carbene},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-107317},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2014},
  abstract  = {Diese Arbeit zeigt die vielf{\"a}ltigen Einsatzm{\"o}glichkeiten des Pr*-Substituenten in Koordinationsverbindungen mit sterisch stark abgeschirmten Molek{\"u}lzentren auf. So wurden neben dem N-heterocyclischen Carben IPr* auch dessen Vorl{\"a}uferverbindungen Pr*NH2 in Imidokomplexen sowie Pr*DAB zur Stabilisierung von {\"U}bergangsmetall- und Hauptgruppenelementverbindungen als Liganden etabliert. Die homoleptisch zweifach NHC-substituierten Komplexe [Pd(IiPr)2] sowie [Pt(IiPr)2] sind synthetisch zug{\"a}nglich und im Gegensatz zu {Ni(IiPr)2} in Substanz isolierbar. Obwohl es sich bei [Pd(IiPr)2] und [Pt(IiPr)2] um niedervalente 14-Elektronenverbindungen handelt, weisen deren Addukte von Neutralliganden teils bemerkenswerte Labilit{\"a}t auf. Im Gegensatz dazu zeichnen sich beide Komplexe durch eine starke Neigung zur oxidativen Addition verschiedenster Substrate unter Ausbildung quadratisch-planarer Metall(II)-Verbindungen aus. So wurden in st{\"o}chiometrischen Reaktionen H-H, C-H, C-X, Si-H, B-H, B-B, P-H und P-P gespalten und die entsprechenden Aktivierungsprodukte charakterisiert.},
  subject      = {Platinkomplexe},
  language  = {de}
}
@phdthesis{Schmidt2013,
  author    = {Schmidt, David},
  title     = {N-Heterocyclische Carbene und NHC stabilisierte Nickelkomplexe in der Aktivierung von Element-Element- und Element-Wasserstoff-Bindungen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-90141},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Die vorliegende Arbeit befasst sich sowohl mit der st{\"o}chiometrischen als auch mit der katalytischen Aktivierung von Element-Element-Bindungen an NHC-stabilisierten Nickel(0) Komplexen.},
  subject      = {Nickelkomplexe},
  language  = {de}
}
@phdthesis{Philipp2022,
  author    = {Philipp, Michael Stephan Maria},
  title     = {N-Heterocyclic Carbenes and Cyclic (Alkyl)(amino)carbenes as Ligands for p-Block Element Compounds},
  doi       = {10.25972/OPUS-28929},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289295},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {In der vorliegenden Arbeit wird die Synthese und Reaktivit{\"a}t neuer NHC- und cAAC-stabilisierter Lewis-S{\"a}ure/Lewis-Base-Addukte von Verbindungen mit Elementen der Gruppen 14 und 15 beschrieben.},
  subject      = {Lewis-Addukt},
  language  = {en}
}
@phdthesis{Kerpen2022,
  author    = {Kerpen, Christoph},
  title     = {- CYANOBORATE - Salze reaktiver Kationen sowie {\"U}bergangsmetallverbindungen},
  doi       = {10.25972/OPUS-16397},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-163974},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Die hier vorliegende Arbeit behandelt die Synthese und Charakterisierung neuer {\"U}bergangsmetall-Borate sowie auf Cyanoborat-Anionen basierende {\"U}bergangsmetallkomplexe und Koordinationsverbindungen mit N-Donor-Liganden und Triphenylphosphan.},
  subject      = {borate},
  language  = {de}
}
@phdthesis{KuntzeFechner2022,
  author    = {Kuntze-Fechner, Maximilian Wolfgang},
  title     = {Reaktivit{\"a}t NHC-stabilisierter Nickel(0)-Komplexe in der C-F-Bindungsaktivierung von Polyfluoraromaten},
  doi       = {10.25972/OPUS-21159},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211597},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Die vorliegende Arbeit befasst sich mit der C-F Bindungsaktivierung von teil und perfluorierten Aromaten an NHC stabilisierten Nickel(0) Komplexen, sowohl in st{\"o}chiometrischen als auch in katalytischen Reaktionen. Der Fokus dieser Arbeit lag auf der Aufkl{\"a}rung der Mechanismen der C-F Bindungsaktivierungsschritte von teil und perfluorierten Aromaten an ein und zweifach NHC stabilisierten Nickel(0) Komplexen, auf dem Einsatz dieser Komplexe in katalytischen Kreuzkupplungs- und Borylierungsreaktionen sowie in der Aufkl{\"a}rung der Mechanismen solcher katalytischen Prozesse. Die im Rahmen dieser Arbeit erzielten Ergebnisse belegen wesentliche Unterschiede im Reaktionsverhalten von Nickel Komplexen in der C-F Bindungsaktivierung: Die Reaktionsmechanismen der mit zwei sterisch unterschiedlich anspruchsvollen NHC Liganden stabilisierten Nickel(0) Komplexe [Ni(iPr2Im)2] (1a) und [Ni(Mes2Im)2] (5) weisen deutliche Unterschiede auf. So erfolgt die Insertion von [Ni(iPr2Im)2] (1a), dem Komplex mit dem weniger anspruchsvolleren Carbenliganden iPr2Im, in die C-F-Bindung von C6F6 nach einem konzertierten und/oder NHC assistierten Reaktionsmechanismus, wohingegen der Nickel(0) Komplex 5 nach einem radikalischen und/oder NHC assistierten Reaktionsmechanismus insertiert. Die Experimente am einfach NHC stabilisierten Nickel(0) Komplex [Ni(Dipp2Im)(η6 C7H8)] 6 belegen, dass die C-F Bindungsaktivierung zun{\"a}chst zu reaktiven mononuklearen Komplexen [Ni(Dipp2Im)(F)(ArF)] f{\"u}hrt, die jedoch allm{\"a}hlich zu dinuklearen, Fluorido verbr{\"u}ckten Nickel(II) Komplexen dimerisieren, die katalytisch nicht aktiv sind. Erst die Aufspaltung dieser Dimere in mononukleare Komplexe mit terminalen Fluoridoliganden f{\"u}hrt zur katalytischen Aktivit{\"a}t. Dabei hat sich gezeigt, dass 5 und 6 vergleichbar gute Katalysatoren in der Nickel vermittelten C-F Borylierung sind und der kritische Schritt der Katalyse die Bereitstellung eines katalytisch aktiven, dreifach koordinierten Nickel Komplexes der Form [Ni(NHC)(F)(ArF)] ist.},
  subject      = {Borylierung},
  language  = {de}
}
@phdthesis{Hennig2022,
  author    = {Hennig, Philipp Thomas},
  title     = {Synthese, Charakterisierung und Eigenschaften neuartiger Mono- und Bis-Pentafluorethylborate sowie Pentafluorethylboran-Addukte},
  doi       = {10.25972/OPUS-19289},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192899},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Diese Arbeit besch{\"a}ftigt sich mit der Synthese, Charakterisierung und Eigeschaften neuer Monopentafluorethylborat-Anionen der Form [C2F5BH2X]- (X= F, Cl, Br), [C2F5BH2(CN)]-, [C2F5BH(CN)2]-, [C2F5BH(CN)X]- (X= F, Cl, Br) und [C2F5B(CN)X2]- (X= Cl, Br)sowie den Bis-pentafluorethylborat-Anionen [(C2F5)2B(OMe)(CN)]-, [(C2F5)2BF(CN)]- und [(C2F5)2B(CN)2]-. Von einigen dieser Verbindungen wurden Ionische Fl{\"u}ssigkeiten basierend auf dem 1-Ethyl-3-methylimidazolium-Kation synthetisiert und deren physikalischen Parameter ausf{\"u}hrlich untersucht. Zudem wurden Pentafluorethylboran-Addukte mit verschiedenen Lewis-Basen der Form C2F5BH2-L (L= THF, SMe2, CH3CN, Pyridin, PPh3, CAAC, IDipp, SIDipp, Me4Im, (iPr)2Me2Im, tBu2Im) hergestellt welche zum Teil als Startmaterialien f{\"u}r die Synthese von Monopentafluorethylboraten verwendet wurden.},
  subject      = {Borate},
  language  = {de}
}
@phdthesis{Paul2018,
  author    = {Paul, Ursula Sofia D{\´e}sir{\´e}e},
  title     = {Studies on the Reactivity of Iridium Bis(phosphinite) Pincer Complexes towards Phosphines, Boranes and their Lewis Adducts and on the Reactivity of Cyclic (Alkyl)(Amino) Carbenes and Nickel Complexes thereof},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-151963},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {The first part of the present work provides an insight into the chemistry of iridium complexes bearing the bis(phosphinite) pincer ligand tBuPOCOP (k3-C6H3-1,3-(OPtBu2)2) towards primary boranes and phosphines as well as phosphine-borane Lewis adducts. It furthermore encloses some more detailed studies on their application as catalyst for the dehydrogenative coupling of the latter compounds. The results presented herein can be divided into three sections: I. synthesis and characterization of aryl dihydroborate ligated iridium(III) complexes II. and aryl phosphine coordinated iridium(I) and dihydrido iridium(III) complexes, III. as well as studies on the reactivity of the parent iridium pincer complexes towards BH3 adducts of primary phosphines, which led to first results in the homogeneous catalytic dehydrocoupling of P-aryl substituted phosphine boranes mediated by such iridium pincer complexes. The second part of the present work provides an insight into the chemistry of cyclic (alkyl)(amino) carbene-stabilized nickel complexes as well as it encloses some more detailed studies on the properties and reactivity of the free carbenes itself. The results presented herein can be divided into four sections: I. synthesis and characterization of cyclic (alkyl)(amino) carbene-stabilized nickel carbonyl complexes, II. which allow the evaluation and quantification of the steric and electronic properties of these cyclic (alkyl)(amino) carbenes, III. first studies on the reactivity of these novel nickel complexes, and IV. investigations on C-F and C-H bond activation at the carbene center of cyclic (alkyl)(amino) carbenes.},
  subject      = {Iridiumkomplexe},
  language  = {en}
}
@phdthesis{Schneider2018,
  author    = {Schneider, Heidi},
  title     = {N-heterocyclische Carbene als Komplex-Liganden in der Chemie des Eisens sowie als Reagenzien in der Chemie der Hauptgruppenelemente},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-155422},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Die vorliegende Arbeit ist in zwei Teile gegliedert und befasst sich im ersten Abschnitt mit der st{\"o}chiometrischen und katalytischen Aktivierung von Element-Element-Bindungen an NHC-stabilisierten Eisen(II)-Komplexen. Im Fokus der Untersuchungen steht hierbei sowohl die Isolierung und Charakterisierung neuartiger NHC-stabilisierter Eisen-Komplexe sowie deren Nutzung als Katalysatoren in der Hydrosilylierung von Carbonylverbindungen und der Hydrophosphanierung von Mehrfachbindungssystemen. Der zweite Teil dieser Arbeit ist der Reaktivit{\"a}t N-heterocyclischer Carbene gegen{\"u}ber Hauptgruppenelement-Verbindungen wie beispielsweise Chlorsilanen, Stannanen, Phosphanen und Alanen gewidmet. Neben der Aufkl{\"a}rung mechanistischer Details der Reaktionen ist die {\"u}bergangsmetallfreie Hydrodefluorierung von Fluoraromaten zentraler Bestandteil dieser Untersuchungen.},
  subject      = {N-heterocyclische Carbene},
  language  = {de}
}
@phdthesis{Budiman2020,
  author    = {Budiman, Yudha Prawira},
  title     = {Applications of Fluorinated Aryl Boronates in Organic Synthesis},
  doi       = {10.25972/OPUS-21757},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217579},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {Fluorinated compounds are an important motif, particularly in pharmaceuticals, as one-third of the top performing drugs have fluorine in their structures. Fluorinated biaryls also have numerous applications in areas such as material science, agriculture, crystal engineering, supramolecular chemistry, etc. Thus, the development of new synthetic routes to fluorinated chemical compounds is an important area of current research. One promising method is the borylation of suitable precursors to generate fluorinated aryl boronates as versatile building blocks for organic synthesis. Chapter 1 In this chapter, the latest developments in the synthesis, stability issues, and applications of fluorinated aryl boronates in organic synthesis are reviewed. The catalytic synthesis of fluorinated aryl boronates using different methods, such as C-H, C-F, and C-X (X = Cl, Br, I, OTf) borylations are discussed. Further studies covering instability issues of the fluorinated boronate derivatives, which are accelerated by ortho-fluorine, have been reported, and the applications of these substrates, therefore, need special treatment. Numerous groups have reported methods to employ highly fluorinated aryl boronates that anticipate the protodeboronation issue; thus, polyfluorinated aryl boronates, especially those containing ortho-fluorine substituents, can be converted into chloride, bromide, iodide, phenol, carboxylic acid, nitro, cyano, methyl esters, and aldehyde analogues. These substrates can be applied in many cross-coupling reactions, such as the Suzuki-Miyaura reaction with aryl halides, the Chan-Evans-Lam C-N reaction with aryl amines or nitrosoarenes, C-C(O) reactions with N-(aryl-carbonyloxy)phthalamides or thiol esters (Liebskind-Srogl cross-coupling), and oxidative coupling reactions with terminal alkynes. Furthermore, the difficult reductive elimination from the highly stable complex [PdL2(2,6-C6F2+nH3-n)2] was the next challenge to be targeted in the homocoupling of 2,6-di-fluoro aryl pinacol boronates, and it has been solved by conducting the reaction in arene solvents that reduce the energy barrier in this step as long as no coordinating solvent or ancillary ligand is employed. Chapter 2 In this chapter, phenanthroline-ligated copper complexes proved to be efficient catalysts for the Suzuki-Miyaura cross-coupling of highly fluorinated aryl boronate esters (ArF-Bpin) with aryl iodides or bromides. This newly developed method is an attractive alternative to the traditional methods as copper is an Earth-abundant metal, less toxic, and cheaper compared to the traditional methods which commonly required palladium catalysts, and silver oxide that is also often required in stoichiometric amounts. A combination of 10 mol\% copper iodide and 10 mol\% phenanthroline, with CsF as a base, in DMF, at 130 ˚C, for 18 hours is efficient to cross-couple fluorinated aryl pinacol boronates with aryl iodides to generate cross-coupled products in good to excellent yields. This method is also viable for polyfluorophenyl borate salts such as pentafluorophenyl-BF3K. Notably, employing aryl bromides instead of aryl iodides for the coupling with fluorinated aryl-Bpin compounds is also possible; however, increased amounts of CuI/phenanthroline catalyst is necessary, in a mixture of DMF and toluene (1:1). A diverse range of π···π stacking interactions is observed in the cross-coupling products partly perfluorinated biaryl crystals. They range from arene-perfluoroarene interactions (2-(perfluorophenyl)naphthalene and 2,3,4-trifluorobiphenyl) to arene-arene (9-perfluorophenyl)anthracene) and perfluoroarene-perfluoroarene (2,3,4,5,6-pentafluoro-2'methylbiphenyl) interactions. Chapter 3 In this chapter, the efficient Pd-catalyzed homocoupling reaction of aryl pinacol pinacol boronates (ArF-Bpin) that contain two ortho-fluorines is presented. The reaction must be conducted in a "noncoordinating" solvent such as toluene, benzene, or m-xylene and, notably, stronger coordinating solvents or ancillary ligands have to be avoided. Thus, the Pd center becomes more electron deficient and the reductive elimination becomes more favorable. The Pd-catalyzed homocoupling reaction of di-ortho-fluorinated aryl boronate derivatives is difficult in strongly coordinating solvents or in the presence of strong ancillary ligands, as the reaction stops at the [PdL2(2,6-C6F2+nH3-n)2] stage after the transmetalations without the reductive elimination taking place. It is known that the rate of reductive elimination of Ar-Ar from [ML2(Ar)(Ar)] complexes containing group-10 metals decreases in the order Arrich-Arpoor > Arrich-Arrich > Arpoor-Arpoor. Furthermore, reductive elimination of the most electron-poor diaryls, such as C6F5-C6F5, from [PdL2(C6F5)2] complexes is difficult and has been a challenge for 50 years, due to their high stability as the Pd-Caryl bond is strong. Thus, the Pd-catalyzed homocoupling of perfluoro phenyl boronates is found to be rather difficult.   Further investigation showed that stoichiometric reactions of C6F5Bpin, 2,4,6-trifluorophenyl-Bpin, or 2,6-difluorophenyl-Bpin with palladium acetate in MeCN stops at the double transmetalation step, as demonstrated by the isolation of cis-[Pd(MeCN)2(C6F5)2], cis-[Pd(MeCN)2(2,4,6-C6F3H2)2], and cis-[Pd(MeCN)2(2,6-C6F2H3)2] in quantitative yields. Thus, it can be concluded that the reductive elimination from diaryl-palladium complexes containing two ortho-fluorines in both aryl rings, is difficult even in a weakly coordinating solvent such as MeCN. Therefore, even less coordinating solvents are needed to make the Pd center more electron deficient. Reactions using "noncoordinating" arene solvents such as toluene, benzene, or m-xylene were conducted and found to be effective for the catalytic homocoupling of 2,6-C6F2+nH3-nBpin. The scope of the reactions was expanded. Using toluene as the solvent, the palladium-catalyzed homocoupling of ArF-Bpin derivatives containing one, two or no ortho-fluorines gave the coupled products in excellent yields without any difficulties. DFT calculations at the B3LYP-D3/def2-TZVP/6-311+g(2d,p)/IEFPCM // B3LYP-D3/SDD/6-31g**/IEFPCM level of theory predicted an exergonic process and lower barrier (< 21 kcal/mol) for the reductive elimination of Pd(C6F5)2 complexes bearing arene ligands, compared to stronger coordinating solvents (acetonitrile, THF, SMe2, and PMe3), which have high barriers ( > 33.7 kcal/mol). Reductive elimination from [Pd(ηn-Ar)(C6F5)2] complexes have low barriers due to: (i) ring slippage of the arene ligand as a hapticity change from η6 in the reactant to ηn (n ≤ 3) in the transition state and the product, which led to less σ-repulsion; and (ii) more favorable π-back-bonding from Pd(ArF)2 to the arene fragment in the transition state. Chapter 4 In this chapter, the efficient Pd-catalyzed C-Cl borylation of aryl chlorides containing two ortho-fluorines is presented. The reactions are conducted under base-free conditions to prevent the decomposition of the di-ortho-fluorinated aryl boronates, which are unstable in the presence of base. A combination of Pd(dba)2 (dba = dibenzylideneacetone) with SPhos (2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl) as a ligand is efficient to catalyze the C-Cl borylation of aryl chlorides containing two ortho-fluorine substituents without base, and the products were isolated in excellent yields. The substrate scope can be expanded to aryl chloride containing one or no ortho-fluorines and the borylated products were isolated in good to very good yield. This method provides a nice alternative to traditional methodologies using lithium or Grignard reagents.},
  subject      = {Homogene Katalyse},
  language  = {en}
}
@phdthesis{Krahfuss2020,
  author    = {Krahfuß, Mirjam Julia},
  title     = {N-Heterocyclic Silylenes as ambiphilic Reagents in Main Group Chemistry and as Ligands in Transition Metal Chemistry},
  doi       = {10.25972/OPUS-21724},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-217246},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {This thesis reports on the applications of a particular N-heterocyclic silylene, Dipp2NHSi (1), as an ambiphilic reagent in main group chemistry and as a ligand in transition metal chemistry. One focus of the work lies in the evaluation of the differences in the reactivity of N-heterocyclic silylenes in main group element and transition metal chemistry in comparison with the in these areas nowadays ubiquitous N-heterocyclic carbenes. The first chapter gives an insight into the reactivity of Dipp2NHSi with respect to different types of main group element compounds. Silylene 1 was reacted with group 13 compounds. Adduct formation was observed with AlI3, Al(C6F5)3 and B(C6F5)3 which led to isolation of Dipp2NHSi·AlI3 (2), Dipp2NHSi·Al(C6F5)3 (3) and Dipp2NHSi·B(C6F5)3 (4). Furthermore, the reactivity of Dipp2NHSi (1) with respect to different elementhalide bonds was investigated. The reaction with elemental bromine and iodine leads to the dihalosilanes Dipp2NHSiBr2 (5) and Dipp2NHSiI2 (6). Utilizing methyl iodide, benzyl chloride and benzyl bromide, the insertion products Dipp2NHSi(I)(Me) (10), Dipp2NHSi(Cl)(benzyl) (11) and Dipp2NHSi(Br)(benzyl) (12) are obtained. Thus, insertion is preferred to reductive coupling with formation of RH2C-CH2R (R = H, Ph) and the corresponding dihalosilane. The reaction of 1 with Me3SnCl leads to the diazabutene {(Me3Sn)N(Dipp)CH}2 (9). The reaction of 1 with Ph2SnCl2 gives exclusively Dipp2NHSiCl2 (8) and cyclic polystannanes (Ph2Sn)n. The reactivity of 1 towards selected 1,3-dipolar compounds was also examined and Dipp2NHSi was reacted with azides of different size. The reaction with adamantyl azide led to the formation of the tetrazoline 13. For the reaction with the sterically less demanding trimethylsilyl azide the azido silane Dipp2NHSi(N(SiMe3)2)(N3) (14) and the degradation product 14* was isolated. The cyclosilamine 15 was formed from the reaction of 1 with 2,6-(diphenyl)phenyl azide. The bonding situation and ligation properties of Dipp2NHSi in transition metal complexes was assessed in the second part of the thesis by means of theoretical calculations and experimental investigations. Calculations on the main electronic features of Me2Im/Me2NHSi and Dipp2NHSi/Dipp2Im revealed significant differences in the frontier orbital region of these compounds, which affect the ligation properties of NHSis in general. It was demonstrated that NHSis show significantly different behaviour concerning their coordination chemistry. In particular, one energetically low lying π-acceptor orbital seems to determine the coordination chemistry of these ligands. To provide experimental support for these calculations, the silylene complexes [M(CO)5(Dipp2NHSi)] (M = Cr 16, Mo 17, W 18) were synthesized from Dipp2NHSi and [M(CO)6] (M = Cr, Mo, W) and the tungsten NHSi complex 18 was compared to the NHC complexes [W(CO)5(iPr2Im)] (19), [W(CO)5(iPr2ImMe)] (20) and [W(CO)5(Me2ImMe)] (21). The bonding of Me2Im and Me2NHSi (= L) to transition metal complexes has been assessed with DFT calculations for the model systems [Ni(L)], [Ni(CO)3(L)], and [W(CO)5(L)]. These studies revealed some common features in the difference between M-NHSi and M-NHC bonding which largely affect the bonding situation in transition metal complexes. NHSis show a propensity for bridging two metal atoms which was demonstrated on three different examples. Dipp2NHSi reacts with [Ni(CO)4] to form the dinuclear silylene-bridged complex [{Ni(CO)2(μ-Dipp2NHSi)}2] (22) upon CO elimination. The reduction of [Ni(η5-C5H5)2] with lithium naphthalenide in the presence of Dipp2NHSi yielded the NHSi-bridged Ni(I) dimer [{(η5 C5H5)Ni(µ-Dipp2NHSi)}2] (23). The dimeric half-sandwich complex [{(η5-C5H5)Fe(CO)2}2] led upon reaction with Dipp2NHSi to the formation of the dinuclear, NHSi-bridged complex [{(η5-C5H5)Fe(CO)}2(µ-CO)(µ-Dipp2NHSi)] (24). The insertion of Dipp2NHSi into metal halide bonds was investigated in a series of manganese complexes [Mn(CO)5(X)] (X = Cl, Br, I). The reaction of Dipp2NHSi with [Mn(CO)5(I)] led to substitution of two carbonyl ligands with Dipp2NHSi (1) to afford the tricarbonyl complex [Mn(CO)3(Dipp2NHSi)2(I)] (25). In 25, the iodide ligand is aligned in the {Mn(CO)3} plane, located between both NHSi silicon atoms. Treatment of [Mn(CO)5(Br)] with two equivalents of Dipp2NHSi afforded the complex [Mn(CO)3(Dipp2NHSi)2(Br)] (26), in which the bromide ligand is distorted towards one of the NHSi ligands. The reaction of the silylene ligand with [Mn(CO)5(Cl)] at room temperature afforded a mixture of two products, [Mn(CO)3(Dipp2NHSi)2(Cl)] (27*) and the insertion product [Mn(CO)4(Dipp2NHSi)(Dipp2NHSi-Cl)] (27). Complete transfer of a halide to the silylene was achieved for the reaction of Dipp2NHSi with [(η5-C5H5)Ni(PPh3)(Cl)] to yield [Ni(PPh3)(η5-C5H5)(Dipp2NHSi-Cl)] (28). Similarly, the reaction with [(η5-C5H5)Fe(CO)2(I)] led to the formation of [(η5 C5H5)Fe(CO)2(Dipp2NHSi-I)] (29).},
  subject      = {Silandiylverbindungen},
  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}
}
@phdthesis{Wirthensohn2023,
  author    = {Wirthensohn, Raphael Sebastian},
  title     = {Metallvermittelte Perfluoralkylierungen und die elektrochemische Fluorierung zu Perfluoralkylverbindungen},
  doi       = {10.25972/OPUS-28664},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-286640},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Diese Arbeit besch{\"a}ftigt sich mit der Synthese und Charakterisierung von mehrfach perfluoralkylierten Verbindungen. Das erste Kapitel behandelt die Kupfer-vermittelte mehrfache Pentafluorethylierung von aromatischen Systemen, sowie die Untersuchung deren Folgechemie. Dabei wurden iodierte Aryl-Derivate mit dem Kupferorganyl CuC2F5 umgesetzt. Mit dieser Methode konnten symmetrisch und unsymmetrisch pentafluorethylierte Anilin- und Phenol-Derivate dargestellt werden. Die Anilin-Derivate wurden zu den entsprechenden Diazoniumsalzen umgesetzt, welche zun{\"a}chst vollst{\"a}ndig charakterisiert und anschließend deren Folgechemie untersucht wurde. Das zweite Kapitel behandelt die Darstellung von Bis(trifluormethyl)sulfon durch elektrochemische Fluorierung mittels des Simons-Prozesses. Dabei wurde der Umsatz der Reaktion durch Verwendung der teilfluorierten Verbindung (Trifluormethyl)methylsulfon als Startmaterial optimiert.},
  subject      = {Perfluoralkylierung},
  language  = {de}
}
@phdthesis{Tendera2023,
  author    = {Tendera, Lukas},
  title     = {NHC-ligated Nickel(0)-Complexes: Bond Activation, Redox Behavior and Catalysis},
  doi       = {10.25972/OPUS-29065},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290654},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {This thesis describes the synthesis and reactivity of bis-NHC ligated nickel(0)-complexes and their application in catalytic cyclization and borylation reactions of alkynes. The focus of the presented work lies on the investigation of the electronic and steric impact of different NHC ligands on the reactivity and catalytic activity of [Ni(NHC)2] complexes. Since d10 ML2 complexes play a decisive role for numerous catalytic reactions, such as the Suzuki-Miyaura cross-coupling, the first chapter provides an overview about the general properties of NHCs and the chemistry of NHC-ligated nickel complexes, their synthesis, characterization, reactivity, and application in catalysis.},
  subject      = {{\"U}bergangsmetallkomplexe},
  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{Foehrenbacher2023,
  author    = {F{\"o}hrenbacher, Steffen Albert},
  title     = {Tris(pentafluorethyl)difluorphosphoran als \(Lewis\)-saure Komponente von Frustrierten \(Lewis\)-Paaren und als Fluorid-Akzeptor in der {\"U}bergangsmetallchemie},
  doi       = {10.25972/OPUS-25160},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251602},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2023},
  abstract  = {Im Rahmen dieser Arbeit wurde die Reaktivit{\"a}t des Phosphorans (C2F5)3PF2 gegen{\"u}ber Lewis-Basen (N-heterozyklische Carbene und Phosphane) und gegen{\"u}ber verschiedenen {\"U}bergangsmetall-Fluoridokomplexen untersucht. Im ersten Teil werden die Lewis-S{\"a}ure/Base-Addukte zwischen (C2F5)3PF2 und verschiedenen N-heterozyklischen Carbenen (NHCs) beschrieben. Der Fokus des zweiten Teils der Arbeit liegt auf der Darstellung kationischer Komplexe ausgehend von neutralen d-Block-Metallfluoriden, welche durch Fluorid-Transfer auf das Lewis-acide (C2F5)3PF2 erfolgt. Hierbei wurden Komplexe verschiedener {\"U}bergangsmetalle (Ti, Ni, Cu) verwendet, wodurch der Fluorid-Transfer auf das Phosphoran quer {\"u}ber die 3d-Reihe untersucht wurde. Im letzten Kapitel dieser Arbeit wurden die Synthese und die Anwendung von Kationen des Typs [(NHC)Cu]+ eingehender untersucht. Dazu wurde zun{\"a}chst die Synthese der Ausgangsverbindungen [(NHC)Cu(F)] modifiziert. Anschließend wurden diese Fluorido-Komplexe auf deren Reaktivit{\"a}t gegen{\"u}ber (C2F5)3PF2 untersucht. Nachfolgend wurden die Reaktivit{\"a}t von [(Dipp2Im)Cu(C6Me6)]FAP in Ligandenaustauschreaktionen bzw. die Synthese von Komplexen [(Dipp2Im)Cu(LB)]FAP (LB = Lewis-Base) eingehender untersucht.},
  subject      = {Phosphorane},
  language  = {de}
}