@phdthesis{Hecht2021,
  author    = {Hecht, Markus},
  title     = {Liquid-Crystalline Perylene Bisimide and Diketopyrrolopyrrole Assemblies},
  doi       = {10.25972/OPUS-21698},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216987},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The research presented in this thesis illustrates that self-assembly of organic molecules guided by intermolecular forces is a versatile bottom-up approach towards functional materials. Through the specific design of the monomers, supramolecular architectures with distinct spatial arrangement of the individual building blocks can be realized. Particularly intriguing materials can be achieved when applying the supramolecular approach to molecules forming liquid-crystalline phases as these arrange in ordered, yet mobile structures. Therefore, they exhibit anisotropic properties on a macroscopic level. It is pivotal to precisely control the interchromophoric arrangement as functions originate in the complex structures that are formed upon self-assembly. Consequently, the aim of this thesis was the synthesis and characterization of liquid-crystalline phases with defined supramolecular arrangements as well as the investigation of the structure-property relationship. For this purpose, perylene bisimide and diketopyrrolopyrrole chromophores were used as they constitute ideal building blocks towards functional supramolecular materials due to their thermal stability, lightfastness, as well as excellent optical and electronic features desirable for the application in, e.g., organic electronics.},
  subject      = {Selbstorganisation},
  language  = {en}
}
@phdthesis{PeethambaranNairSyamala2021,
  author    = {Peethambaran Nair Syamala, Pradeep},
  title     = {Bolaamphiphilic Rylene Bisimides: Thermodynamics of Self-assembly and Stimuli-responsive Properties in Water},
  doi       = {10.25972/OPUS-21342},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213424},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The present thesis demonstrates how different thermodynamic aspects of self-assembly and stimuli-responsive properties in water can be encoded on the structure of π-amphiphiles, consisting of perylene or naphthalene bisimide cores. Initially, quantitative thermodynamic insights into the entropically-driven self-assembly was studied for a series of naphthalene bisimides with UV/Vis and ITC measurements, which demonstrated that their thermodynamic profile of aggregation is heavily influenced by the OEG side chains. Subsequently, a control over the bifurcated thermal response of entropically driven and commonly observed enthalpically driven self-assembly was achieved by the modulation of glycol chain orientation. Finally, Lower Critical Solution Temperature (LCST) phenomenon observed for these dyes was investigated as a precise control of this behavior is quintessential for self-assembly studies as well as to generate 'smart' materials. It could be shown that the onset of phase separation for these molecules can be encoded in their imide substituents, and they are primarily determined by the supramolecular packing, rather than the hydrophobicity of individual monomers.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Shen2021,
  author    = {Shen, Chia-An},
  title     = {Dicyanomethylene Squaraines: Aggregation and G-Quadruplex Complexation},
  doi       = {10.25972/OPUS-24359},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-243599},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Squaraine dyes have attracted more attention in the past decade due to their strong and narrow absorption and fluorescence along with the easily functionalized molecular structure. One successful approach of core functionalization is to replace one oxygen of the squaric carbonyl group with a dicyanomethylene group, which shifts the absorption and emission into the near infrared (NIR) region and at the same time leads to a rigid, planar structure with C2v symmetry. However, such squaraines tend to aggregate cofacially in solution due to dispersion forces and dipole-dipole interactions, usually leading to H-type exciton coupling with undesired blue-shifted spectrum and quenched fluorescence. Therefore, the goal of my research was the design of dicyanomethylene-substituted squaraine dyes that self-assemble into extended aggregates in solution with J-type coupling, in order to retain or even enhance their outstanding optical properties. Toward this goal, bis(squaraine) dyes were envisioned with two squaraine units covalently linked to trigger a slip-stacked packing motif within the aggregates to enable J-type coupling. In my first project, bis(squaraine) dye BisSQ1 was synthesized, in which two dicyanomethylene squaraine chromophores are covalently linked. Concentration and temperature-dependent UV/Vis/NIR spectroscopy experiments reveal that BisSQ1 undergoes cooperative self-assembly resulting in J-type aggregates in a solvent mixture of toluene/1,1,2,2-tetrachloroethane (TCE) (98:2, v/v). The J type exciton coupling is evident from the significantly red shifted absorption maximum at 886 nm and the fluorescence peak at 904 nm. In conclusion, this was a first example to direct squaraine dye aggregation in solution to the more desired slip-stacked packing leading to J-type exciton coupling by simply connecting two dyes in a head-to-tail bis chromophore structure. Connecting two squaraine dyes with an additional phenylene spacer (BisSQ2) leads to two different polymorphs with very distinct absorption spectra upon cooling down a solution of BisSQ2 in a solvent mixture of toluene/TCE (98:2, v/v) with different rates. Accordingly, rapid cooling resulted in rigid helical nanorods with an absorption spectrum showing a panchromatic feature, while slow cooling led to a sheet-like structure with a significant bathochromic shift in the absorption spectrum. It was discovered that the conventional molecular exciton model failed to explain the panchromatic absorption features of the nanorods for the given packing arrangement, therefore more profound theoretical investigations based on the Essential States Model (ESM) were applied to unveil the importance of intermolecular charge transfer (ICT) to adequately describe the panchromatic absorption spectrum. Moreover, the red-shift observed in the spectrum for the sheet-like structure can be assigned to the interplay of Coulomb coupling and ICT-mediated coupling. Furthermore, the same bis-chromophore strategy was adopted for constructing an NIR-II emitter with a bathochromically-shifted spectrum. In chloroform, BisSQ3 exhibits an absorption maximum at 961 nm with a significant bathochromic shift (1020 cm-1) compared to the reference mono-squaraine SQ, indicating intramolecular J-type coupling via head-to-tail arrangement of two squaraine dyes. Moreover, BisSQ3 shows a fluorescence peak at 971 nm with a decent quantum yield of 0.33\%. In less polar toluene, BisSQ3 self-assembles into nanofibers with additional intermolecular J-type coupling, causing a pronounced bathochromic shift with absorption maximum at 1095 nm and a fluorescence peak at 1116 nm. Thus, connecting two quinoline-based squaraines in a head-to-tail fashion leads to not only intra-, but also intermolecular J-type exciton coupling, which serves as a promising strategy to shift the absorption and emission of organic fluorophores into the NIR-II window while retaining decent quantum yields. In conclusion, my research illustrates based on squaraine dyes how a simple modification of the molecular structure can significantly affect the aggregation behavior and further alter the optical properties of dye aggregates. Elongated supramolecular structures based on dicyanomethylene substituted squaraine dyes were successfully established by covalently linking two squaraine units to form a bis-chromophore structure. Then, a simple but efficient general approach was established to direct squaraine dye aggregation in solution to the more desired slip-stacked packing leading to J-type exciton coupling by directly connecting two squaraine dyes in a head-to-tail fashion without spacer units. Moreover, the additional spacer between the squaraine dyes in BisSQ2 allowed different molecular conformations, which leads to two different morphologies depending on the cooling rates for a hot solution. Hence, this is a promising strategy to realize supramolecular polymorphism. In general, it is expected that the concept of constructing J-aggregates by the bis-chromophore approach can be extended to entirely different classes of dyes since J-aggregates possess a variety of features such as spectral shifts into the NIR window, fluorescence enhancement, and light harvesting, which are commonly observed and utilized for numerous fundamental studies and applications. Moreover, the insights on short-range charge transfer coupling for squaraine dyes is considered of relevance for all materials based on alternating donor-acceptor π-systems. The panchromatic spectral feature is in particular crucial for acceptor-donor-acceptor (ADA) dyes, which are currently considered as very promising materials for the development of bulk heterojunction solar cells.},
  subject      = {Squaraine},
  language  = {en}
}
@phdthesis{Sapotta2021,
  author    = {Sapotta, Meike},
  title     = {Perylene Bisimide Cyclophanes: Recognition of Alkaloids, Aggregation Behavior in Aqueous Environment and Guest-Mediated Chirality Transfer},
  doi       = {10.25972/OPUS-20002},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200028},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {Inspired by the fact that sufficient solubility in aqueous media can be achieved by functional substitution of perylene bisimides (PBIs) with polar groups, one of the essential aims of this thesis was the design and successful synthesis of the new water-soluble PBI cyclophanes [2PBI]-1m and [2PBI]-1p, which are appended with branched, hydrophilic oligoethylene glycol (OEG) chains. Subsequently, the focus was set on the elucidation of properties of PBI cyclophane hosts which are also of relevance for recognition processes in biological systems. The performance of the new amphiphilic PBI cyclophane [2PBI]-1p as synthetic receptors for various natural aromatic alkaloids in aqueous media was thoroughly investigated. Alkaloids represent a prominent class of ubiquitous nitrogen containing natural compounds with a great structural variety and diverse biological activity. As of yet, no chromophore host acting as a molecular probe for a range of alkaloids such as harmine or harmaline is known. In addition, the self-association behavior of cyclophane host [2PBI]-1m and its reference monomer in water was studied in order to gain insights into the thermodynamic driving forces affecting the self-assembly process of these two PBI systems in aqueous environment. Moreover, the chirality transfer upon guest binding previously observed for a PBI cyclophane was investigated further. The assignment of the underlying mechanism of guest recognition to either the induced fit or conformational selection model was of particular interest.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Kaufmann2019,
  author    = {Kaufmann, Christina},
  title     = {Discrete Supramolecular Architectures of Bay-linked Perylene Bisimide Dimers by Self-Assembly and Folding},
  doi       = {10.25972/OPUS-17300},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173005},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Supramolecular self-assembly of perylene bisimide (PBI) dyes via non-covalent forces gives rise to a high number of different PBI architectures with unique optical and functional properties. As these properties can be drastically influenced by only slightly structural changes of the formed supramolecular ensembles (Chapter 2.1) the controlled self-assembly of PBI dyes became a central point of current research to design innovative materials with a high potential for different applications as for example in the fields of organic electronics or photovoltaics. As PBI dyes show a strong tendency to form infinite aggregated structures (Chapter 2.2) the aim of this thesis was to precisely control their self-assembly to create small, structurally well-defined PBI assemblies in solution. Chapter 2.3 provides an overview on literature known strategies that were established to realize this aim. It could be demonstrated that especially backbone-directed intra- and intermolecular self-assembly of covalently linked Bis-PBI dyes evolved as one of the most used strategies to define the number of stacked PBI chromophores by using careful designed spacer units with regard to their length and flexibility. By using conventional spectroscopic methods like UV/Vis and fluorescence experiments in combination with NMR measurements an in-depth comparison of the molecular and optical properties in solution both in the non-stacked and aggregated state of the target compounds could be elucidated to reveal structure-property relationships of different PBI architectures. Thus, it could be demonstrated, that spacer units that pre-organize two PBI chromophores with an inter-planar distance of r < 7 {\AA} lead to an intramolecular folding, whereas linker moieties with a length between 7 to 11 {\AA} result in an intermolecular self-assembly of the respective Bis-PBIs dyes via dimerization to form well-defined quadruple PBI pi-stacks. Hence, if the used spacer units ensure an inter-planar distance r > 14 {\AA} larger oligomeric PBI pi-stacks are generated. In Chapter 4 a detailed analysis of the exciton coupling in a highly defined H-aggregate quadruple PBI pi-stack is presented. Therefore, bay-tethered PBI dye Bis-PBI 1 was investigated by concentration-dependent UV/Vis spectroscopy in THF and toluene as well as by 2D-DOSY-NMR spectroscopy, ESI mass spectrometry and AFM measurements confirming that Bis-PBI 1 self-assembles exclusively into dimers with four closely pi-stacked PBI chromophores. Furthermore, with the aid of broadband fluorescence upconversion spectroscopy (FLUPS) ensuring broadband detection range and ultrafast time resolution at once, ultrafast Frenkel exciton relaxation and excimer formation dynamics in the PBI quadruple pi-stack within 1 ps was successfully investigated in cooperation with the group of Dongho Kim. Thus, it was possible to gain for the first time insights into the exciton dynamics within a highly defined synthetic dye aggregate beyond dimers. By analysing the vibronic line shape in the early-time transient fluorescence spectra in detail, it could be demonstrated that the Frenkel exciton is entirely delocalized along the quadruple stack after photoexcitation and immediately loses its coherence followed by the formation of the excimer state. In Chapter 5 four well-defined Bis-PBI folda-dimers Bis-PBIs 2-4 were introduced, where linker units of different length (r < 7 {\AA}) and steric demand were used to gain distinct PBI dye assemblies in the folded state. Structural elucidation based on in-depth UV/Vis, CD and fluorescence experiments in combination with 1D and 2D NMR studies reveals a stacking of the two PBI chromophores upon folding, where geometry-optimized structures obtained from DFT calculations suggest only slightly different arrangements of the PBI units enforced by the distinct spacer moieties. With the resulting optical signatures of Bis-PBIs 2-4 ranging from conventional Hj-type to monomer like absorption features, the first experimental proof of a PBI-based "null-aggregate" could be presented, in which long- and short-range exciton coupling fully compensate each other. Hence, the insights of this chapter pinpoint the importance of charge-transfer mediated short-range exciton coupling that can significantly influence the properties of pi-stacked PBI chromophores In the last part of this thesis (Chapter 6), spacer-controlled self-assembly of four bay-linked Bis-PBI dyes Bis-PBIs 5-8 into well-defined supramolecular architectures was investigated, where the final aggregate structures are substantially defined by the nature of the used spacer units. By systematically extending the backbone length from 7 to 15 {\AA} defining the inter-planar distance between the tethered chromophores, different assemblies from defined quadruple PBI pi-stacks to larger oligomeric pi-stacks could be gained upon aggregation. In conclusion, the synthesis of nine covalently linked PBI dyes in combination with a detailed investigation of their spacer-mediated self-assembly behaviour in solution concerning structure-properties-relationships was presented within this thesis. The results confirm a strong exciton coupling in different types of Bis-PBI architectures e.g. folda-dimers or highly defined quadruple pi-stacks, which significantly influences their optical properties upon self-assembly.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Kirchner2019,
  author    = {Kirchner, Eva},
  title     = {Discrete Supramolecular Stacks by Self-Assembly and Folding of Bis(merocyanine) Dyes},
  doi       = {10.25972/OPUS-15941},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159419},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {The present thesis describes the development of a strategy to create discrete finite-sized supramolecular stacks of merocyanine dyes. Thus, bichromophoric stacks of two identical or different chromophores could be realized by folding of bis(merocyanine) dyes and their optical properties were discussed in terms of exciton theory. Quantum chemical calculations revealed strong exciton coupling between the chromophores within the homo- and hetero-π-stacks and the increase of the J-band of the hetero-dimers with increasing energy difference between the excited states of the chromophores could be attributed not only to the different magnitudes of transition dipole moments of the chromophores but also to the increased localization of the excitation in the respective exciton state. Furthermore, careful selection of the length of the spacer unit that defines the interplanar distance between the tethered chromophores directed the self-assembly of the respective bis(merocyanines) into dimers, trimers and tetramers comprising large, structurally precise π-stacks of four, six or eight merocyanine chromophores. It could be demonstrated that the structure of such large supramolecular architectures can be adequately elucidated by commonly accessible analysis tools, in particular NMR techniques in combination with UV/vis measurements and mass spectrometry. Supported by TDDFT calculations, the absorption spectra of the herein investigated aggregates could be explained and a relationship between the absorption properties and the number of stacking chromophores could be established based on exciton theory.},
  subject      = {Merocyanine},
  language  = {en}
}
@phdthesis{KlotzbachverhFimmel2018,
  author    = {Klotzbach [verh. Fimmel], Stefanie},
  title     = {Synthese und Charakterisierung kovalent organischer K{\"a}figverbindungen basierend auf Tribenzotriquinacen-Einheiten},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166034},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Porous functional materials are promising candidates for applications in the areas of heterogeneous catalysis, sensing, gas storage and separation, or membranes. As one class of suchlike materials, organic cage compounds have attracted attention because of their unique properties compared to extended frameworks. The tribenzotriquinacene (TBTQ) scaffold possessing three orthogonal indane moieties provides a suitable building block for the efficient synthesis of organic cage compounds. In this thesis the synthesis of molecular cubes, tetrahedra and bipyramids by crosslinking the catechol units of TBTQ with various diboronic acids is reported. Structure and shape of the molecular objects are thereby determined by the geometry of the diboronic acids. Notably, both narcissistic and social self-sorting phenomena could be observed for ternary mixtures of building blocks. In addition host-guest complexation was observed for the trigonal bipyramid cage. Fullerenes C60 as well as C70 were almost quantitively encapsulated. Further investigations of this behaviour showed a preference for C60 in a competitive situation.},
  subject      = {K{\"a}figverbindungen},
  language  = {de}
}
@phdthesis{Dhara2017,
  author    = {Dhara, Ayan},
  title     = {Stimuli-Responsive Self-Assembly and Spatial Functionalization of Organic Cages Based on Tribenzotriquinacenes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-154762},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {Within this thesis, synthetic strategies for self-assembled organic cage compounds have been developed that allow for both stimuli-responsive control over assembly/disassembly processes and spatial control over functionalization. To purposefully operate the reversible assembly of organic cages, boron-nitrogen dative bonds have been exploited for the formation of a well-defined, discrete bipyramidal organic assembly in solution. Thermodynamic association equilibria for cage formation have been investigated by Isothermal Titration Calorimetry (ITC). Temperature-dependent NMR studies revealed a reversible cage opening upon heating and quantitative reassembly upon cooling. For the spatial functionalization of organic cages, two divergent molecular building units have been designed and synthesized, namely tribenzotriquinacene derivatives possessing a terminal alkyne moiety at the apical position and a meta-diboronic acid having a pyridyl group at the 2-position. Facile access to a variety of apically functionalized tribenzotriquinacenes has been illustrated by post-synthetic modifications at the terminal alkyne group by Sonogashira cross-coupling and azide-alkyne click reactions. Finally, these apically functionalized tribenzotriquinacene building blocks have been implemented into boronate ester-based organic cage compounds showing modular exohedral functionalities.},
  subject      = {Selbstorganisation},
  language  = {en}
}
@phdthesis{Goerl2015,
  author    = {G{\"o}rl, Daniel},
  title     = {Hydrophobe Effekte bolaamphiphiler Rylenbisimide},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123172},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Die Selbstorganisation von amphiphilen Molek{\"u}len z{\"a}hlt zu den am intensivsten bearbeiteten Forschungsgebieten der Supramolekularen Chemie. Die faszinierenden supramolekularen Architekturen der Natur zeigen eindrucksvoll, wie neuartige Funktionen durch das Zusammenspiel wohl-definierter Molek{\"u}lensembles in einer w{\"a}ssrigen Umgebung entstehen. Es ist bekannt, dass der hydrophobe Effekt dabei eine entscheidende Rolle in der Selbstorganisation spielt und somit die Funktion eines Systems wesentlich bestimmt. Obwohl die Komplexit{\"a}t der bekannten Beispiele aus der Natur unerreicht ist, wurden in den letzten Jahren unz{\"a}hlige k{\"u}nstliche supramolekulare Architekturen basierend auf amphiphilen Molek{\"u}len erschaffen, mit vielf{\"a}ltigen Anwendungsm{\"o}glichkeiten an der Schnittstelle von Chemie, Biologie und Physik. Darunter er{\"o}ffnen insbesondere amphiphile π-konjugierte Systeme einen einfachen Zugang zu vielf{\"a}ltigen Strukturen, da im w{\"a}ssrigen Medium starke π-π-Wechselwirkungen als strukturbildendes Element ausgenutzt werden k{\"o}nnen. Vor allem wegen vielversprechender Anwendungsm{\"o}glichkeiten spiegelt sich die Selbstorganisation solcher Systeme in einem hohen Forschungsinteresse wider. Dennoch ist das Wirken des hydrophoben Effekts in der Selbstassemblierung amphiphiler π-konjugierter Molek{\"u}le weitgehend unverstanden. Die vorliegende Arbeit befasste sich daher mit der Frage, welche physikochemischen Grundprinzipien die Bildung von supramolekularen Polymeren basierend auf amphiphilen π-konjugierten Molek{\"u}len in Wasser steuern und wie der hydrophobe Effekt die Funktionalit{\"a}t solcher Strukturen beeinflusst. Bolaamphiphile Perylenbisimide (PBIs) und Naphthalinbisimide (NBIs) erwiesen sich dabei f{\"u}r das Molek{\"u}ldesign als besonders geeignet, weil sie vergleichsweise einfach dargestellt werden k{\"o}nnen, ihre hohe Symmetrie weniger komplexe Assoziationsprozesse begr{\"u}ndet und die Untersuchung ihrer Selbstassemblierung im w{\"a}ssrigen Medium weiterhin einen Vergleich erlaubt, wie sich der hydrophobe Effekt bez{\"u}glich unterschiedlich großen π-Systemen auswirkt. Es konnte gezeigt werden, dass OEG-basierte Rylenbisimide unter bestimmten strukturgeometrischen Voraussetzungen eine entropiegetriebene Aggregation aufweisen, wenn die Freisetzung von Wassermolek{\"u}len aus einer wohl-definierten Hydrath{\"u}lle ausreicht, um den Enthalpiegewinn aus den im w{\"a}ssrigen Medium verst{\"a}rkten Dispersionswechselwirkungen zwischen den π-Fl{\"a}chen zu {\"u}bertreffen. Im vorliegenden Fall wurde dies durch das Pinsel-Strukturmotiv der symmetrisch angebrachten Imidsubstituenten erreicht, f{\"u}r die sich damit einhergehend eine g{\"a}nzlich andere Temperaturabh{\"a}ngigkeit beobachten ließ und somit eine g{\"a}nzlich andere Funktionalit{\"a}t, als man sie aus organischen L{\"o}sungsmitteln kennt. Wasser als L{\"o}sungsmittel f{\"u}hrt also nicht nur zu einer signifikanten Bindungsverst{\"a}rkung, sondern {\"o}ffnet Zugang zu supramolekularen Systemen mit neuartigen Funktionen. Die entropiegetriebene Freisetzung von Wassermolek{\"u}len konnte daher im Rahmen dieser Arbeit ausgenutzt werden, um gleichzeitig die intrinsische Ordnung im π-Stapel von PBIs zu erh{\"o}hen, was anhand eines temperatursensorischen Hydrogels anschaulich demonstriert wurde. Dar{\"u}ber hinaus stellte sich heraus, dass Wasser ein geeignetes L{\"o}sungsmittel zur Darstellung supramolekularer Kompositmaterialien ist. Wie anhand sich instantan bildender Co-Aggregate gezeigt wurde, ist die entropiegetriebene Assemblierung der entscheidende Faktor zur Darstellung von komplexeren supramolekularen Strukturen, die {\"u}berdies einen Schritt hin zu den hochkomplexen multimolekularen Anordnungen der Natur darstellen.},
  subject      = {Selbstorganisation},
  language  = {de}
}
@phdthesis{Rest2015,
  author    = {Rest, Christina},
  title     = {Self-assembly of amphiphilic oligo(phenylene ethynylene)-based (bi)pyridine ligands and their Pt(II) and Pd(II) complexes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133248},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {The presented work in the field of supramolecular chemistry describes the synthesis and detailed investigation of (bi)pyridine-based oligo(phenylene ethynylene) (OPE) amphiphiles, decorated with terminal glycol chains. The metal-ligating property of these molecules could be exploited to coordinate to Pd(II) and Pt(II) metal ions, respectively, resulting in the creation of novel metallosupramolecular π-amphiphiles of square-planar geometry. The focus of the presented studies is on the self-assembly behaviour of the OPE ligands and their corresponding metal complexes in polar and aqueous environment. In this way, the underlying aggregation mechanism (isodesmic or cooperative) is revealed and the influence of various factors on the self-assembly process in supramolecular systems is elucidated. In this regard, the effect of the molecular design of the ligand, the coordination to a metal centre as well as the surrounding medium, the pH value and temperature is investigated.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Rehm2015,
  author    = {Rehm, Stefanie},
  title     = {Spermine-functionalized Perylene Bisimide Dyes: Synthesis and Self-assembly in Water},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123201},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {The main objective of this thesis was the design and synthesis of perylene bisimide dyes with sufficient water-solubility for the construction of self-assembled architectures in aqueous solutions. Beside these tasks another goal of this project was the control over the self-assembly process in terms of aggregate size and helicity, respectively. Within this thesis an appropriate synthesis for spermine-functionalized perylene bisimide dyes was developed and conducted successfully. The characterization of these building blocks and their course of self-assembly were investigated by NMR, UV/Vis and fluorescence spectroscopy as well as by atomic force and transmission electron microscopy. For the better understanding of the experimental results theoretical calculations were performed.},
  subject      = {Perylenderivate},
  language  = {en}
}
@phdthesis{Shao2012,
  author    = {Shao, Changzhun},
  title     = {Programming Self-assembly: Formation of Discrete Perylene Bisimide Aggregates},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69298},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {The objective of this thesis focuses on the development of strategies for precise control of perylene bisimide (PBI) self-assembly and the in-depth elucidation of structural and optical features of discrete PBI aggregates by means of NMR and UV/Vis spectroscopy. The strategy for discrete dimer formation of PBIs is based on delicate steric control that distinguishes the two facets of the central perylene surface. The strategy applied in this thesis for accessing discrete PBI quadruple and further oligomeric stacks relies on backbone-directed PBI self-assembly. For this purpose, two tweezer-like PBI dyads bearing the respective rigid backbones, diphenylacetylene (DPA) and diphenylbutydiyne (DPB), were synthesized. The distinct aggregation behavior of these structurally similar PBI dyads can be ascribed to the intramolecular distance between the two PBI chromophores imparted by the DPA and DPB spacers.},
  subject      = {Farbstoff},
  language  = {en}
}
@phdthesis{Schlosser2012,
  author    = {Schlosser, Felix},
  title     = {Synthese und Charakterisierung kovalent gebundener Perylenbisimid-Makrozyklen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71811},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Eine Reihe von Acetylen-verkn{\"u}pften Perylenbisimid(PBI)-Makrozyklen mit unterschiedlicher Ringgr{\"o}ße wurde durch Palladium-katalysierte Homokupplung synthetisiert und mit Hilfe von Recycling-GPC getrennt. Diese Makrozyklen wurden durch NMR-Spektroskopie und Massenspektrometrie charakterisiert und weiterhin die photophysikalischen Eigenschaften durch UV/Vis-Absorptions- und Fluoreszenzemissions-Messungen untersucht. Die Selbstorganisation dieser PBI-Makrozyklen zu hochgeordneten Nanostrukturen auf HOPG-Oberfl{\"a}chen wurde mittels Rasterkraftmikroskopie untersucht.},
  subject      = {Makrocyclische Verbindungen},
  language  = {de}
}
@phdthesis{Schmidt2011,
  author    = {Schmidt, Ralf},
  title     = {Hamilton-Receptor-Mediated Self-Assembly of Merocyanine Dyes into Supramolecular Polymers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-56265},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Die Selbstorganisation von Merocyaninfarbstoffen zu supramolekularen Polymeren wurde untersucht. Dabei konnte die Anordnung der hoch dipolaren Farbstoffe durch die Verwendung von verschiedenen Kombinationen von Wasserstoffbr{\"u}ckenbindungsmotiven und dipolarer Aggregation der Chromophore gesteuert.},
  subject      = {Selbstorganisation},
  language  = {en}
}
@phdthesis{SafontSempere2010,
  author    = {Safont Sempere, Marina Montserrat},
  title     = {Chiral self-sorting of atropo-enantiomeric perylene bisimide dyes},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-55359},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2010},
  abstract  = {This thesis included the synthesis of conformationally stable chiral perylene bisimide (PBI) dyes, the study of their optical properties in solution and their chiral self-sorting behaviour in nonpolar solvents in which dimerization via pi-pi-stacking takes place. Furthermore, the influence of PBI core chirality on the properties of these dyes in the condensed state has been also studied. We have demonstrated and quantified the prevalence of chiral self-recognition over self-discrimination in pi-stacking dimerization of PBIs. It has been shown that this self-recognition event is compromised by the increasing flexibility of the structures related to the size of the OEG bridging units. Moreover, the inherent chirality of these PBIs has been proven to strongly influence their condensed state properties, for which large differences between the pure enantiomers and the racemates were revealed, as well as between the different bridged macrocyclic PBIs.},
  subject      = {Farbstoff},
  language  = {en}
}
@phdthesis{Sengupta2011,
  author    = {Sengupta, Sanchita},
  title     = {Bio-inspired Zinc Chlorin Dye Assemblies for Supramolecular Electronics},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-66935},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2011},
  abstract  = {Chlorophylls are the most important pigments owing to their involvement in photosynthesis. They perform multiple functions that arise due to their optical and redox as well as packing properties. Semisynthetic zinc chlorins investigated in this thesis are the counterparts for the natural protein-free bacteriochlorophyll (BChl) c assemblies in light-harvesting (LH) systems in bacterial chlorosomes. The major advantage of the zinc chlorin model compounds over the native BChls lies in their facile semisynthetic accessibility from chlorophyll a (Chl a), their higher chemical stability and the possibility to influence their packing by suitable chemical modifications of peripheral side chains. Whilst the favorable excitonic properties and the suitability of ZnChl and natural BChl c dye aggregates for long distance exciton transport are well documented, charge transport properties of aggregates of semisynthetic ZnChls are hitherto unexplored. The present study involves structural elucidations of aggregates of a variety of semisynthetic zinc chlorin derivatives in solution, in solid state and on surfaces by combination of spectroscopic, crystallographic and microscopic techniques, followed by investigation of charge transport properties and conductivities of these aggregates. Chart 1 shows the different ZnChls synthesized in this work that are functionalized with hydroxy or methoxy substituents at 31 position and contain different substituents at the 172-position benzyl ester functional group. The self-assembly of these dyes is strongly dependent upon their chemical structures. While ZnChls 1a, 2a, 3, which are functionalized with 31-hydroxy group bearing dodecyl and oligoethylene glycol side chains form well-soluble rod aggregates, the corresponding 31-methoxy functionalized counterparts 1b, 2b form stacks in solution and on surfaces. These supramolecular polymers have been studied in detail in Chapter 3 by UV/Vis and circular dichroism (CD) spectroscopy and dynamic light scattering (DLS). These studies provided useful insights into the aggregation process of these two types of aggregates. Whereas 31-hydroxy functionalized ZnChl 1a self-assemble into rod aggregates via an isodesmic mechanism, corresponding stack aggregates of ZnChl 1b are formed by a cooperative nucleation-elongation pathway. Detailed electron microscopic studies such as transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) provided unequivocal evidence for hollow tubular nanostructures of water-soluble 31-hydroxy zinc chlorin 3 aggregates for the first time. The measured tube diameter of ~ 5-6 nm of these aggregates is in excellent agreement with electron microscopy data of BChl c rod aggregates in chlorosomes (Chloroflexus aurantiacus, diameter ~ 5-6 nm) and thus complied with the tubular model postulated by Holzwarth and Schaffner... In concord with their highly organized structures, micrometer-scale one dimensionality, robust nature and efficient charge transport capabilities, these self-assembled ZnChl nanotubular, stack and liquid crystalline assemblies are highly promising for supramolecular electronic applications. Research efforts in utilizing these assemblies for (opto)electronic device fabrication, for instance, in organic field effect transistors, should thus be rewarding in the future...},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Li2009,
  author    = {Li, Xueqing},
  title     = {Hydrogen Bond-directed Self-assembly of Perylene Bisimide Organogelators},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-43727},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2009},
  abstract  = {Perylene bisimide (PBI) dyes are a widely used class of industrial pigments, and currently have gained significant importance for organic-based electronic and optical devices. Structural modification at the PBI core results in changes of the optical and electronic properties, which enable tailored functions. Moreover, the aggregation behavior of PBIs is alterable and controllable to achieve new materials, among which organogels are of particular interest because of their potential for applications as supramolecular soft materials. In this work, new PBI-based organic gelators were designed, synthesized, and characterized, and the aggregation behaviors under different conditions were intensively studied by various spectroscopic and microscopic methods. In chapter 2, a brief overview is given on the structural and functional features of organogel systems. The definition, formation and reversibility of organogels are introduced. Some examples on dye based organogel are selected, among which PBI-based organogelators reported so far are especially emphasized. Some basic knowledges of supramolecular chirality are also overviewed such as characterization, amplification, and symmetry breaking of the chiral aggregates. According to our former experiences, PBIs tend to form aggregates because the planer aromatic cores interact with one another by pi-pi interaction. In chapter 3, a new PBI molecule is introduced which possesses amide groups between the conjugated core and periphery alkyl chains. It is found that well oriented aggregates are formed by hydrogen bonding and the pi-pi interaction of the cores. These interactions enable the aggregates to grow in one-dimension forming very long fibers, and these fibers further intercross to 3D network structures, e.g., organogels. In comparison to the very few PBI-based gelators reported before, one advantage of this gelator is that, it is more versatile and can gelate a wide range of organic solvents. Moreover, the well-organized fibers that are composed of extended \&\#960;-stacks provide efficient pathways for n-type charge carriers. Interestingly, AFM studies reveal that the PBI molecules form well-defined helical fibers in toluene. Both left-handed (M) and right-handed (P) helicities can be observed without any preference for one handedness because the building block is intrinsically achiral. In chapter 4, we tried to influence the M/P enantiomeric ratio by applying external forces. For example, we utilized chiral solvents to generate chiral aggregates with a preferential handedness. AFM analysis of the helices showed that a enantiomeric ratio of about 60: 40 can be achieved by aggregation in chiral solvents R- or S-limonene. Moreover, the long aggregated fibres can align at macroscopic level in vortex flows upon rotary stirring In chapter 5, bulky tetra-phenoxy groups are introduced in the bay area of the PBI gelator. The conjugated core of the new molecule is now distorted because of the steric hindrance. UV/Vis studies reveal a J-type aggregation in apolar solvents like MCH due to intermolecular pi-pi-stacking and hydrogen-bonding interactions. Microscopic studies reveal formation of columnar aggregates in apolar solvent MCH, thus this molecule lacks the ability to form gels in this solvent, but form highly fluorescent lyotropic mesophases at higher concentration. On the other hand, in polar solvents like acetone and dioxane, participation of the solvent molecules in hydrogen bonding significantly reduced the aggregation propensity but enforced the gel formation. The outstanding fluorescence properties of the dye in both J-aggregated viscous lyotropic mesophases and bulk gel phases suggest very promising applications in photonics, photovoltaics, security printing, or as fluorescent sensors. In chapter 6, we did some studies on combining PBI molecules with inorganic gold nanorods. Gold nanorods were synthesized photochemically. By virtue of the thioacetate functionalized PBIs, the rods were connected end to end to form gold nanochains, which were characterized by absorption spectra and TEM measurement. Such chromophore-nanorod hybrids might be applied to guide electromagnetic radiation based on optical antenna technology.},
  subject      = {Perylenderivate},
  language  = {en}
}
@phdthesis{Lohr2008,
  author    = {Lohr, Andreas},
  title     = {Self-Assembly of Merocyanines : Thermodynamic and Kinetic Insights into the Formation of Well-Defined Dye Aggregates},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-28964},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {The present thesis demonstrates the potential of dipolar aggregation of merocyanine dyes as novel directional and specific supramolecular binding motif for the creation of more elaborate supramolecular architectures beyond simple dimers. Furthermore, the self-assembly studies into bis(merocyanine) nanorods gave new insights into the kinetics of morphogenesis in supramolecular aggregates.},
  subject      = {Supramolekulare Chemie},
  language  = {en}
}
@phdthesis{Roeger2007,
  author    = {R{\"o}ger, Cornelia},
  title     = {Bioinspired Light-Harvesting Zinc Chlorin Rod Aggregates Powered by Peripheral Chromophores},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-26760},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2007},
  abstract  = {Artificial light-harvesting (LH) systems have been obtained by self-assembly of naphthalene diimide-functionalized zinc chlorin dyads and triad in nonpolar, aprotic solvents. UV-vis, CD, and steady-state emission spectroscopy as well as atomic force microscopy showed that rod-like structures are formed by excitonic interactions of zinc chlorin units, while the appended naphthalene diimide dyes do not aggregate at the periphery of the cylinders. In all cases, photoexcitation of the enveloping naphthalene diimides at 540 and 620 nm, respectively, was followed by highly efficient energy-transfer processes to the inner zinc chlorin backbone, as revealed by time-resolved fluorescence spectroscopy on the picosecond time-scale. As a consequence, the LH efficiencies of zinc chlorin rod aggregates were increased by up to 63\%. The effective utilization of solar energy recommends these biomimetic systems for an application in electronic materials on the nanoscale.},
  subject      = {Farbstoff},
  language  = {en}
}
@phdthesis{Huber2007,
  author    = {Huber, Valerie},
  title     = {Selbstorganisation von semisynthetischen Zinkchlorinen zu biomimetischen Lichtsammelsystemen und definierten Nanostrukturen},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-24517},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2007},
  abstract  = {Diese Arbeit besch{\"a}ftigt sich mit der Selbstorganisation von Zinkchlorin-Farbstoffen, welche sich strukturell von Chlorophyllen ableiten. Im Gegensatz zu allen anderen bakteriellen und pflanzlichen Lichtsammelpigmenten ist es den Bakteriochlorophyllen c, d und e der Lichtsammelsysteme gr{\"u}ner phototropher Bakterien m{\"o}glich, allein durch nichtkovalente Wechselwirkungen zwischen den Farbstoff-Molek{\"u}len, ohne die Beteiligung von Proteinen, r{\"o}hrenf{\"o}rmige Antennensysteme auszubilden, welche die am dichtest gepackten und effizientesten Lichtsammelsysteme in der Natur darstellen. Um einen Betrag zur Aufkl{\"a}rung dieser biologisch wichtigen Aggregate zu leisten, wurden im ersten Teil dieser Arbeit Zinkchlorine als Modellverbindungen f{\"u}r BChl c hergestellt. Mit den neu synthetisierten Zinkchlorinen ist es gelungen, Modellsysteme der nat{\"u}rlichen BChl-Selbstorganisate herzustellen, welche sich im Gegensatz zu den bisher in der Literatur beschriebenen Zinkchlorin-Aggregaten durch eine gute und dauerhafte L{\"o}slichkeit auszeichnen. Diese Eigenschaft erlaubte es sowohl spektroskopische als auch mikroskopische Untersuchungen zur Aufkl{\"a}rung der Aggregatstruktur durchzuf{\"u}hren. Durch Rasterkraftmikroskopie an den Zinkchlorin Aggregaten konnte erstmals ein mikroskopischer Beweis der stabf{\"o}rmigen Struktur von Aggregaten dieser Substanzklasse erhalten werden. Der zweite Teil dieser Arbeit besch{\"a}ftigt sich mit Zinkchlorinen, denen aufgrund einer methylierten 31-Hydroxy-Gruppe die F{\"a}higkeit zur R{\"o}hrenbildung fehlt, die aber durch Koordinationsbindungen und p-p-Wechselwirkungen weiterhin Stapel bilden k{\"o}nnen. Temperaturabh{\"a}ngige UV/Vis- und CD-spektroskopische Studien offenbarten die reversible Bildung von l{\"o}slichen, chiralen Zinkchlorin-Stapelaggregaten. Rasterkraft- und rastertunnelmikroskopische Untersuchungen zeigen die Bildung von zwei Typen p-gestapelter Aggregate auf hoch geordnetem Graphit.},
  subject      = {Farbstoff},
  language  = {de}
}
@phdthesis{Chen2006,
  author    = {Chen, Zhijian},
  title     = {pi-Stacks Based on Self-Assembled Perylene Bisimides : Structural, Optical, and Electronic Properties},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-19940},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2006},
  abstract  = {As a traditional industrial pigment, perylene bisimide (PBI) dyes have found wide-spread applications. In addition, PBI dyes have been considered as versatile and promising functional materials for organic-based electronic and optic devices, such as transistors and solar cells. For these novel demands, the control of self-organization of this type of dye and the investigation of the relationship between the supramolecular structure and the relevant optical and electronic properties is of great importance. The objective of this thesis focuses on gaining a better understanding of structural and functional properties of pi-stacks based on self-assembling PBIs. Studies include the synthesis and characterization of new functional PBI dyes, their aggregation in solution, in liquid crystalline state and on surfaces, and their fluorescence and charge transport properties. An overview of the formation, thermodynamics and structures of pi-stacks of functional pi- conjugated molecules in solution and in liquid crystalline phases is given in Chapter 2. Chapters 3 and 4 deal with the pi-pi aggregates of new, highly fluorescent PBIs without core-substituents. In Chapter 3, the self-assembly of a PBI with tridodecylphenyl substituents at imide N atoms both in solution and condensed phase has been studied in great detail. In condensed state, the dye exhibits a hexagonal columnar liquid crystalline (LC) phase as confirmed by DSC, OPM and X-ray diffraction analysis. The columnar stacking of this dye has been further confirmed by atomic force microscopy (AFM) where single columns could be well resolved The charge transport properties this dye have been investigated by pulse radiolysis-time resolved microwave conductivity (PR-TRMC) measurements. To shed more light on the nature of the pi-pi interaction of the unsubstituted PBIs, solvent depend aggregation properties have been investigated in Chapter 4. The studies are further extended from core-unsubstituted PBIs to core-substituted ones (Chapter 5 and 6). In Chapter 5, a series of highly soluble and fluorescent core-twisted PBIs that bear the same trialkylphenyl groups at the imide positions but different bay-substituents and were synthesized. These compounds are characterized by distortions of the perylene planes with dihedral angles in the range of 15-37° according to crystallographic data and molecular modeling studies. In contrast to the extended oligomeric aggregates formed for planar unsubstituted PBIs, this family of dyes formed discrete pi-pi-stacked dimers in apolar methylcyclohexane as concentration-dependent UV/Vis measurements and VPO analysis revealed. The Gibbs free energy of dimerization can be correlated with the twist angles of the dyes linearly. In condensed state, several of these PBIs form luminescent rectangular or hexagonal columnar liquid crystalline phases with low isotropization temperatures. The core-twisting effect on semiconducting properties has been examined in Chapter 6. In this chapter, a comparative study of the electrochemical and the charge transport properties of a series of non-substituted and chlorine-functionalized PBIs was performed. While Chapters 3-6 focus on one-component dye systems, Chapter 7 explored the possibility of a supramolecular engineering of co-aggregates formed by hydrogen-bonded 2:1 and 1:1 complex of oligo(p-phenylene vinylene)s (OPVs) and PBIs. Covalently linked donor-acceptor dye arrays have been prepared for comparison. Concentration and temperature-dependent UV/Vis spectroscopy revealed all hydrogen-bonded and covalent systems form well-ordered J-type aggregates in methylcyclohexane. With these hydrogen-bonded OPV-PBI complexes, fibers containing p-type and n-type molecules can be prepared on the nano-scale (1-20 nm). For the 2:1 OPV-PBI hydrogenbonded arrays hierarchically assembled chiral superstructures consisting of left-handed helical pi-pi co-aggregates (CD spectroscopy) of the two dyes that further assemble into right-handed nanometer-scale supercoils in the solid state (AFM study) have been observed. All of these well-defined OPV-PBI assemblies presented here exhibit photoinduced electron transfer on sub-ps timescale, while the electron recombination differs for different systems.Thus, it was suggested that such assemblies of p- and n-type semiconductors might serve as valuable nanoscopic functional units for organic electronics.},
  subject      = {Perylenderivate},
  language  = {en}
}
@phdthesis{Kriegisch2005,
  author    = {Kriegisch, Volker},
  title     = {Electron transfer processes between organic redox centres and electrodes via active bridges in self-assembled monolayers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-15892},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2005},
  abstract  = {Cyclovoltammetrische Messungen der Ferrocenalkylthiole 1 - 3 belegen, dass homogene, gemischte Monolagen aus redoxaktiven Verbindungen und redoxinaktiven Alkylthiolen gebildet werden. Die von Creager et al. bestimmten ET Raten der Ferrocenalkylthiole 1 - 3 konnten hierbei verifiziert werden. Wie erwartet erfolgt eine Abnahme der ET Geschwindigkeit bei einer Kettenverl{\"a}ngerung des Alkylspacers von 2 nach 3. Eine unterschiedliche Konnektivit{\"a}t zwischen Redoxzentrum und Alkylspacer, z. B. die Einf{\"u}hrung einer Carbonyl-Funktion im Falle von 1, unter Beibehaltung der Kettenl{\"a}nge zeigt keinen bemerkbaren Einfluß auf den ET. Trotzt vergleichbaren Abstands der aromatischen Ferrocenthiole 4 und 5 zu der C8-Alkyl-Verbindung 2 zwischen Redoxzentrum und Elektrode, weisen diese aufgrund ihrer starken Konjugation sehr hohe ET Geschwindigkeiten auf. Die elektronischen Kopplungsfaktoren selbst deuten auf einen nichtadiabtischen ET zwischen Redoxzentrum und Elektrode hin. Wie erwartet kommt es zu einem Anwachsen der Kopplungsfaktoren bei sich verk{\"u}rzender Kettenl{\"a}nge oder bei Einf{\"u}hrung konjugierter Spacersysteme. Zusammenfassend kann gesagt werden, dass Erfahrungen hinsichtlich der Pr{\"a}paration der Monolagen gesammelt, die gemessenen ET Raten f{\"u}r der literaturbekannten Verbindungen 1 - 3 best{\"a}tigt und diese Informationen auf die konjugierten Verbindungen 4 und 5 angewandt werden konnten. Im zweiten Teil wurden die Triarylamin- (29, 32) und Phenothiazinalkylthiole (35) bez{\"u}glich ihres ET Verhaltens in gemischten Monolagen untersucht. Mittels Cyclovoltammetrie konnte gezeigt werden, daß einheitlich geformte, verd{\"u}nnte Monolagen vorliegen. Die ET Raten der Triarylamin- (29, 32) und Phenithiazinalkylthiole (35) sind jedoch um den Faktor 10 bis 100 h{\"o}her als vergleichbare Ferrocenalkylthiole gleicher Kettenl{\"a}nge [1, 2], wohingegen f{\"u}r Monolagen, welche [Ru(bpy)2(pp)]+-Alkythiole enthalten, {\"a}quivalente Werte gefunden wurden [3]. Die ET Geschwindigkeit wird von zwei Parametern beeinflusst: dem elektronischen Kopplungsmatrixelement und der Regorganisationsenergie \&\#61548;\&\#61472; [4]. Die ET Geschwindigkeit in Donor-substituierten Alkylthiolen wird haupts{\"a}chlich durch \&\#61548; beeinflusst und sogar kleine {\"A}nderungen dieser zeigen eine große Auswirkung auf die zu untersuchenden Prozesse. Aus diesem Grund wird eine Zunahme der ET Geschwindigkeit von Ferrocen (hohe Reorganisationsenergie) {\"u}ber die Phenothiazinverbindung 35 und [Ru(bpy)2(pp)]+ zu den Triarylaminchromophoren 29 und 32 (niedrige Reorganisationsenergie) beobachtet. Weiterhin spielt, im Gegensatz zu Beobachtung von Creager et al. an {\"a}quivalenten Ferrocenverbingungen, die Anbindung des Redoxzentrums an den Alkylspacer eine bedeutende Rolle. Im Falle der elektronenreichen Ether-verbr{\"u}ckten Verbindung 29 wird der ET nicht alleine durch \&\#61548;, sondern ebenso durch mesomere Effekte bestimmt. Bei 29 kommt es durch Lokalisation der positiven Ladung nahe der Ether Funktion formal zu einer Kettenverk{\"u}rzung um eine „Methyleneinheit", welche schließlich in h{\"o}heren ET Geschwindigkeiten resultiert. Im dritten Teil dieser Dissertation wurde ein Serie „molekularer Dr{\"a}hte" bestehend aus Methoxy- oder Chlorid-substituierten Triarylamin- und Phenothiazinverbindungen mit unterschiedlichen Br{\"u}ckeneinheiten und Br{\"u}ckenl{\"a}ngen zwischen Redoxzentrum und Ankerfunktion dargestellt und im Hinblick auf ihr ET Verhalten untersucht. Durch cyclovoltammetrische und UV/Vis-spektroskopische Untersuchungen konnte gezeigt werden, dass sowohl die Oxidationspotentiale als auch die energetischen Zust{\"a}nde der Chromophore recht gut durch Einf{\"u}hrung unterschiedlicher Redoxzentren und Br{\"u}ckeneinheiten beeinflusst werden k{\"o}nnen. Trotz erfolgreicher Kontrolle der Dichte der Chromophoreinheiten in den gemischten Monolagen konnte nur f{\"u}r die Verbindungen 49, 52 und 87 mit Nitril-substituierten Br{\"u}ckeneinheiten verl{\"a}ssliche ET Geschwindigkeiten erhalten werden. Bei diesen Chromphoren ist ein Absinken der ET Geschwindigkeit bei zunehmender Dichte der redoxaktiven Molek{\"u}le in den gemischten Monolagen zu beobachten, welche auf eine {\"A}nderung der Adsorptionsgeometrie hindeutet. Bei zunehmender Packungsdichte der Chromophore f{\"u}hrt dies zu einer aufrechteren Stellung der redoxaktiven Spezies. F{\"u}r alle anderen Verbindungen konnten keine Werte aufgrund der zu schnellen ET Geschwindigkeiten ermittelt werden. Konformelle, wie auch die sehr geringe Abstandsabh{\"a}ngigkeit des ET, resultieren in hohen ET Geschwindigkeiten oder auch ung{\"u}nstige HOMO-LUMO Energien bez{\"u}glich des Donors, der Br{\"u}cke und der Elektrode sind Gr{\"u}nde f{\"u}r dieses Verhalten. Die Tatsache, dass Verbindung 49 und 52 beinahe die gleichen Geschwindigkeitskonstanten des ETs unabh{\"a}ngig von der Anzahl der Br{\"u}ckeneinheiten (n = 2, n = 3) besitzen, deutet darauf hin, dass ein Hopping-Prozess stattfindet, bei welchem eine geringere L{\"a}ngenabh{\"a}ngigkeit des ETs als bei eine Superexchange-Mechanismus zu erwarten ist.},
  subject      = {Monoschicht},
  language  = {en}
}