Ce travail de thèse est principalement centré sur l’étude des processus photophysiques fondamentaux de nouveaux composés organiques à transfert de charge dérivés de styrylpyridine, réalisée grâce à des mesures de fluorescence résolue en temps à l’échelle picoseconde et d’absorption transitoire à l’échelle femtoseconde. Nous nous sommes tout d’abord intéressés au comportement des états excités de deux nouvelles hémicyanines. Les molécules de diméthoxystyrylpyridine méthylées ont montré l’établissement d’un équilibre entre les conformations syn et anti différent à l’état excité comparé à l’état fondamental, représenté par un temps de décroissance rapide de fluorescence. La deuxième constante de temps correspond à la dépopulation de l’état excité par les voies non radiatives telles que l’isomérisation et le twist du donneur de charge (effet « loose-bolt »). Concernant le dérivé de styrylpyridinium où le groupement phényl a été remplacé par diméthlaminothiophene, nos études ont prouvé l’implication du mouvement de rotation du groupement méthylpyridinium ainsi que l’intervention du croisement inter-système comme voies de relaxation. Dans un second temps, nous nous sommes penchés sur les propriétés de complexation de la molécule de styrylpyridine sur laquelle a été substitué un éther-couronne. Nos études nous ont permis de mettre en évidence la présence de deux centres de complexation (un au centre de la couronne, l’autre sur l’azote de la pyridine) montrant une sélectivité différente vis-à-vis des cations métalliques. Les stoechiométries ont pu être confirmées par une analyse des temps de réorientation des complexes formés. Après avoir étudié les divers composés constituant des « briques » élémentaires en vue de systèmes supramoléculaires plus élaborés, nous nous sommes intéressés à leurs éventuelles applications avec l’étude de systèmes pour la collecte et le transfert d’énergie. Nous avons tout d’abord démontré l’existence d’un transfert d’énergie ultra-rapide (180 fs à 6 ps) et ultra-efficace (>99.7%) dans des systèmes bichromophoriques contenant deux styrylpyridines avec un éther-couronne et asymétrisés par l’introduction d’un cation Mg2+ dans une seule couronne. Celui-ci se fait de la partie complexée vers la partie non complexée par interaction coulombienne. Une autre application envisagée réside dans la construction de complexes à métaux de transition pour le stockage d’énergie ou le stockage d’information. Nous avons tout d’abord étudié la formation d’un système supramoléculaire basé sur le phénanthroline et contenant quatre éther-couronnes libres. Nous avons mis en évidence l’existence d’un équilibre entre états singulets et triplets excités dans ces composés complexés avec Cuivre(I) ou Argent(I). Dans un second temps, nous avons étudié la formation de complexes liant deux bipyridines substitués contenant un éther-couronne à un ion Fe2+. Un tel complexe présente des propriétés de transition de spin BS?HS. Nos études ont ensuite révélé la formation de complexes à métaux de transition de taille nanométrique lors de l’ajout d’ions Ba2+. / This Ph.D. work mainly deals with the study of fundamental photophysical processes of new styrylpyridine-type organic compounds showing charge transfer, realised using picosecond fluorescence and femtosecond transient absorption. We were interested first in the excited-state behaviour of two new hemicyanines. Methylated dimethoxystyrylpyridines molecules showed the establishment of an equilibrium between syn and anti conformations which is different in the excited state compared to the ground state, represented by a fast relaxation time of fluorescence. The second time constant corresponds to depopulation of the the excited state by non-radiative pathways as isomerization and donor twist (« loose-bolt »). Concerning styrylpyridinium derivative where phenyl group was replaced by dimethylaminothiophene, our studies proved involvment of rotation of methylpyridinium group and intersystem crossing as relaxation pathways. Secondly, we were interested in complexation properties of ether-crown susbstituted styrylpyridine molecule. Our studies showed the presence of two complexation centers (one in the center of the crown, the other one on the nitrogen of pyridine) having a different selectivity for metallic cations. Stoichiometries were confirmed by analysis of the reorientation times of formed complexes. After the study of our different compounds as elementary « building–blocks » for more complex supramolecular systems, we were interested in their potential applications with the study of systems for collection and energy transfer. First, we highlighted the existence of an ultra fast (180 fs to 6 ps) and ultra efficient (>99.7%) intramolecular energy transfer in bichromophoric systems containing two ether-crowned styrylpyridines and dissymetrised by binding of a Mg2+ cation in only one crown. It occurs from the complexed part to the non-complexed one by coulombic interaction. Another envisaged application can be the construction of complexes containing transition metals for energy or information storage. We studied first the building of a supramolecular system based on phenanthroline and containing four free ether-crowns We also proved that there exists an equilibrium between singlet and triplet excited states in these compounds complexed with Copper(I) or Silver(I). Secondly, we studied formation of complexes binding two ether-crown substituted bipyridines to a Fe2+ ion. Such a complex has got some spin crossover properties. Then, we showed that the addition of Ba2+ ions induce formation of transition metals complexes with nanometric size.

The understanding of self-assembly processes is important for fabrication of well-defined structures with new functionalities for applications in the area of biomedical sciences, material sciences and electronics. In this thesis, two types of self-assembly processes are described: (1) self-assembly of fullerene derivatives in water and (2) self-assembly on surfaces using layer-by-layer (LbL) approach. The various interactions and parameters involved in the self-assembly are detailed in the introductory chapter 1. The various internal parameters like molecular geometry, intramolecular and intermolecular forces that guides the self-assembly process of amphiphiles in water are discussed. The experimental procedures used in the present thesis for the fabrication of nanostructures via self-assembly approach are also described. In the later part of the chapter, the LbL technique for fabrication of thin films and microcapsules is reviewed where various interactions involved in the growth of LbL assembly are discussed. The effect of ionic strength and pH on the growth and property of LbL assemblies is elaborated. A brief discussion of the materials used in the thesis ‒ fullerene, bovine serum albumin (BSA) and nanocrystalline cellulose (NCC) is also provided The self-assembly behaviour of amphiphilic fullerene derivatives are described in chapter 2. Fullerene is anisotropically substituted with five polar hydroxyl groups using organo-copper reagent. The derivative can interact in water via the van der Waals and hydrophobic interactions of the fullerene moiety as well as the intermolecular hydrogen bonding among the hydroxyl groups and also with water. The penta-hydroxy fullerene derivative self-assembles in water as vesicular structures. The size of these vesicles can be varied by modifying the kinetics of self-assembly which was done by changing the rate of addition of non-solvent (water) to the solution of the fullerene derivative. In the second derivative, the hydroxyl groups are substituted with less polar methoxy groups. The penta-methoxy fullerene derivative cannot participate in inter-molecular hydrogen bonding formation unlike the penta-hydroxy derivative but there is possibility of hydrogen bond formation with water where oxygens on methoxy group can act as hydrogen bond acceptor. The penta-methoxy fullerene does not show any vesicle formation in water. The computational simulation studies were carried out on the two fullerene derivatives to understand the self-assembly behaviour of these two derivatives. Furthermore, the vesicle structures formed by the penta-hydroxy fullerene derivative are used for entrapment of hydrophobic polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and also hydrophilic dye, Rhodamine B. In both the cases, fluorescence quenching is observed due to electron transfer reaction with fullerene and hence these fullerene vesicles can be used to study the effect of confinement on electron transfer reactions and other chemical dynamics. The layer-by-layer self-assembly approach for the fabrication of biopolymeric thin films and microcapsules is discussed in the chapters 3 to 6. The biocompatible nanoparticles and nanofibers were used as the components of the assembly. In chapter 3, we have described fabrication of thin film of bovine serum albumin (BSA) nanoparticles via LbL approach using biopolymer chitosan as the complementary polymer. The driving force for the assembly growth of the assembly was the electrostatic and complementary hydrogen bond formation between the two components. The idea of incorporating nanoparticles in the thin film was that the nanoparticles can act as reservoirs for functional materials. The films were loaded with anticancer drug doxorubicin and show pH dependent release of the drug. The various interactions involved in the LbL assembly of BSA nanoparticles and polymers were investigated towards understanding the growth mechanism of the assembly in chapter 4. The understanding of the interactions involved in the assembly formation is important in order to modify the conditions of the assembly for enhancing the growth. It is inferred from the study reported in this chapter that not only the interaction of nanoparticles with polymers but also the inter-particle interactions are important factors in determining the growth of LbL assembly of nanoparticles/polymers. The growth of the assembly is enhanced on minimizing the inter-particle repulsions, which was achieved in case of BSA nanoparticles by modifying the pH of the assembly. We also utilized the LbL self-assembly approach for the delivery of lipophilic drugs. The lipophilic drugs are difficult to administer in the body due to their poor water solubility and hence show poor pharmacokinetic profile. The methods for incorporating hydrophobic drugs in LbL assembled thin films and microcapsules are described in chapters 5 and 6. In chapter 5, hydrophobic molecules binding property of albumin has been exploited for solubilisation of a water-insoluble molecule, pyrene (model drug) and hydrophobic drug, curcumin, by preparation of non-covalent conjugates with BSA. The interaction with BSA provided negative zeta potential to the previously uncharged molecules and hence they can be incorporated in the LbL assembled thin films and microcapsules using electrostatic as well as hydrogen bonding interaction with biopolymer, chitosan. The fabrication of protein encapsulated stable microcapsules with hydrophobic molecules incorporated in the shell of the microcapsules has also been demonstrated. The microcapsules were further capable of loading hydrophilic molecules like Rhodamine B. Thus, this approach can be employed for fabrication of multi-agent carrier for hydrophobic and hydrophilic drugs as well as therapeutic macromolecules. In chapter 6, we have incorporated nanocrystalline cellulose (NCC) LbL assembled thin films and microcapsules. The assembly formed was porous in nature due to the nano-fibrous morphology of NCC. The nanoassemblies can act as potential drug delivery carrier, which has been demonstrated by loading anticancer drug doxorubicin, and a lipophilic drug, curcumin. Doxorubicin hydrochloride, the salt form of the drug, doxorubicin, has good water solubility and hence can be postloaded in the assembly by diffusion from its aqueous solution. In the case of curcumin, which has limited solubility in water, a stable aqueous dispersion of the drug was prepared via noncovalent interaction with NCC prior to incorporation in the LbL assembly. The interaction of various other lipophilic drugs with NCC was analysed computationally.

La synthèse de particules polyuréthane par organo-catalyse dans le dioxyde de carbone supercritique a été étudiée. Des réactions modèles ont été préalablement conduites et suivies par spectroscopie infrarouge in situ dans le CO2 supercritique afin d'identifier les catalyseurs organiques de réaction d'uréthanisation les plus efficients. Une série de polymères siliconés CO2-phile, porteurs de la fonction organo-catalytique en bout de chaîne (organo-catasurfs), a ensuite été préparée et testée dans le CO2 supercritique pour la polymérisation en dispersion de polyuréthane. / The organocatalysed synthesis of polyurethane particles in supercritical carbon dioxide has been studied. Model reactions were first carried out in supercritical CO2 and monitored by in situ infrared spectroscopy in order to indentify the most efficient catalysts for the urethanisation reaction. A series of CO2-philic silicone polymers, end-functionalised with the organocatalytic group (organocatasurfs), were then synthesised and tested in supercritical CO2 for the dispersion polymerisation of polyurethane.

Dans la première partie nous décrivons la synthèse et l'évaluation biologique de nouveaux inhibiteurs de l'agrégation plaquettaire, composés dont la structure a été établie en partant du 12-HETE et du 13-HODE. Dans la seconde partie nous développons de nouvelles méthodologies pour la préparation de molécules contenant des motifs CF₂R. Tout d'abord une stratégie très flexible a été mise au point pour la préparation de composés gem-difluorobisaryliques et de leurs analogues hétéroaromatiques. Elle est basée sur l'emploi d'intermédiaires gem-difluoropropargyliques faciles d'accès. Par une séquence de Diels-alder-aromatisation on obtient les molécules cibles de la première série. Pour la seconde, des réactions de cycloaddition dipolaire 1,3 ont été utilisées. A partir de ces intermédiaires, des chimiothèques ciblées de molécules fluorées ont été préparées. Nous nous sommes intéressés ensuite à la synthèse de composés fluorés fonctionnalisés et chiraux à travers des réactions d'organocatalyse asymétrique. A partir d'énals gem-difluorés des réactions de Diels-Alder et des additions 1,4 asymétriques ont été réalisées avec succès. / The first part of the thesis deals with the synthesis and biological evaluation of new platelets aggregation inhibitors, based on 12-HETE, 13-HODE and their analogues. In the second part we are interested in novel methodologies for the preparation of CF₂-containing molecules : First, a flexible strategy for the synthesis of gem-difluoro-bisarylic derivatives and heteroaromatic analogues was designed based on the easy synthesis and the reactivity of gem-difluoro propargylic intermediates, which by Diels-Alder cycloaddition and 1,3-dipolar cycloadditions afforded respectively the bisarylic and mixed arylic heteroarylic scaffolds. In addition, two small libraries were constructed around a bisarylic scaffold as representative examples. Second, we were interested in the synthesis of optically active functionalized molecules containing a gem-difluoro group, using asymmetric organocatalysis protocols. After preparation of the gem-difluoro enals, from their difluoropropargylic precursors, asymmetric organocalytic Diels-Alder cycloaddition and 1,4-conjugated additions were successfully performed.

Bibliographische Beschreibung und Referat Frosch, W. Synthese und Reaktionsverhalten Bis(alkinyl)-Metallocen-stabilisierter monomerer Organo-Kupfer(I)-Verbindungen Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Dissertation, 2001, 103 Seiten. In der vorliegenden Arbeit werden Synthese und Reaktionsverhalten von hetero-metallischen Ti(IV)-Cu(I)-Komplexen der Art {[Ti](CCR1)2}CuX {[Ti] = (h5-C5H4SiMe3)2Ti; R1 = einfach gebundener organischer Rest; X = anorganischer, organischer oder metallorganischer Rest} beschrieben. Diese Verbindungen können zwei bis fünf Übergangsmetall-Atome enthalten, welche durch verschiedene Komplex-Liganden und auf unterschiedliche Bindungsweise miteinander verknüpft sind. Zentrale Bausteine der in dieser Arbeit untersuchten Komplexe sind die metallorganischen pi-Pinzetten [Ti](CCR1)2 und der monomere Kupfer(I)-Methyl- Komplex {[Ti](CCR1)2}CuCH3. Letzterer kann in vielfältiger Weise zur Synthese verschiedener bis(h2-alkin)-stabilisierter Kupfer(I)-Verbindungen verwendet werden, welche im besonderen Interesse der vorliegenden Untersuchungen standen. Des Weiteren war das Augenmerk auf das Reaktionsverhalten von [Ti](CCR1)2 gegenüber ÜM-Komplexen von Metallen der Gruppe 12 des Periodensystems der Elemente in verschiedenen Oxidationsstufen gerichtet. Die im Rahmen dieser Arbeit durchgeführten Untersuchungen lassen sich dabei in vier Schwerpunkte gliedern: 1) Mehrfach Carboxylat-funktionalisierte Ti(IV)-Cu(I)-Komplexe: Synthese, Fest-körperstruktur und Reaktionsverhalten. 2) Reaktion von Bis(alkinyl)-Titanocenen mit Metall-Verbindungen der Gruppe 10-12 des Periodensystems der Elemente. 3) Donor-funktionalisierte Bis(alkinyl)-Titanocene und deren Reaktionsverhalten. 4) Monomeres Kupfer(I)-Methyl als synthetisches Werkzeug: Synthese einer breiten Palette unterschiedlicher Kupfer(I)-Systeme. Stichworte: metallorganisch, heterometallisch, pi-Systeme, Metallocene, Alkine, Bis(alkinyl)-Titanocene, metallorganische pi-Pinzetten, Koordinationsverbindungen, Kupfer(I), monomere Kupfer(I)-Organyle.

Cette thèse propose un regard nouveau sur l'étude du mécanisme de conversion de spin à l'aide de la diffraction des rayonnements X et neutronique. Cette technique est mise en œuvre de manière originale et permet d'obtenir des résultats inédits. Notre travail s'articule autour de l'exploration pionnière de cristaux à conversion de spin par la diffraction des neutrons, par l'obtention de films structuraux via de la diffraction X multi-températures et par l'étude de l'évolution de la qualité cristalline au fil des transitions. Les avancées de ce travail concernent aussi bien le niveau fondamental, apportant des informations de base sur le phénomène de conversion de spin, que le niveau expérimental, ouvrant de nouvelles voies d'investigation, en allant jusqu'à des éléments intéressants le domaine de l'application industrielle. Au niveau expérimental, l'étude multi-structurale proposée a permis, grâce à l'acquisition d'une quantité d'information considérable, l'élaboration d'un film de la conversion de spin, permettant de visualiser quasiment en continu toutes les modifications structurales induites par la conversion de spin. Les résultats fondamentaux qui en ont découlé concernent le mécanisme de commutation depuis l'échelle atomique jusqu'à celle de l'arrangement cristallin. L'étude de ce dernier a aussi été réalisée par diffraction neutronique qui permet la description des liaisons hydrogène dont le rôle, pourtant clef dans les matériaux moléculaires, est aujourd'hui peu étudié dans les complexes à conversion de spin. Enfin, la fatigabilité cristalline en relation avec le phénomène de conversion de spin a été abordée via un protocole expérimental pionnier mis en œuvre au laboratoire. Appliquée à l'évolution d'un complexe à conversion graduelle, cette approche expérimentale a mis en évidence un vieillissement du cristal au fil des cycles de conversion, et semble révéler un lien entre fatigabilité et structure macroscopique du système. / This thesis suggests a new perspective on the study of the mechanism of spin conversion using the diffraction of X-rays and neutrons. This technique is implemented in an original way and leads to unprecedented results. Our work focuses on the pioneer exploration of spin conversion complexes by neutron diffraction, by obtaining structural films via multi-temperature X-ray diffraction and by the study of the crystalline quality over spin crossovers. The progress of this work relates to both the fundamental level, providing crucial information on the phenomenon of spin conversion, and the experimental level, opening new avenues of investigation. At the experimental level, the multi-structural study has led, through the acquisition of a considerable quantity of data, to the production of a spin-crossover film, allowing to visualize almost continuously all structural changes induced by the spin conversion. Fundamental results concern the switching mechanism from the atomic to the the crystal packing scale. The study of the crystal packing was also carried out by neutron diffraction, which allows the description of hydrogen bonds whose role, yet key in molecular materials, is nowadays only rarely studied in the spin crossover complex field. Finally, the crystalline fatigability in connection with the phenomenon of spin crossover has been addressed through an experimental protocol implemented in the laboratory. Applied to the evolution of a gradual spin crossover complex, this experimental approach has highlighted the crystal aging over conversion cycles, and makes a link between fatigability and macroscopic structure of the system.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-11-12T19:43:53Z No. of bitstreams: 1 CARLOS MAURÍCIO ROCHA BARROSO - DISSERTAÇÃO PPGECA 1994..pdf: 33322816 bytes, checksum: 8d3b97e59953825ca5f62b7f53c9c80d (MD5) / Made available in DSpace on 2018-11-12T19:43:53Z (GMT). No. of bitstreams: 1 CARLOS MAURÍCIO ROCHA BARROSO - DISSERTAÇÃO PPGECA 1994..pdf: 33322816 bytes, checksum: 8d3b97e59953825ca5f62b7f53c9c80d (MD5) Previous issue date: 1994-04 / Esta dissertação apresenta os resultados de uma pesquisa sobre a contaminação do "Aquífero Barreiras" por organo clorados, no Polo Cloroquímico de Alagoas — PCA. As substâncias químicas envolvidas no processo que são produtos que apresentam grande poder tóxico, comprometeram a qualidade do aquífero, gerando um impacto ambiental significativo e da maior gravidade. Dentre tais contaminantes, destacam-se os compostos 1,2 dicloroetano (1,2 - DCE), 1,2 dicloropropano (1,2 — DCP) e 1,2,3 tricloropropano (1,2,3 — TOE), por apresentarem maiores valores em suas concentrações e por conseguinte, alvo da pesquisa. O aquífero Barreiras, na área do PCA, possui uma espessura média de 20 metros, constituindo—se litologicamente por um "pacote" areno—argiloso, intercalado por níveis descontínuos de material argiloso, sendo caracterizado como um aquífero freático. O modelo de fluxo adotado, baseado no método das diferençasfinitas - algoritmo IADI — (Kinzelbach, 19S6), utilizou os dados extraídos de relatórios da empresa Paranaguá — Engenharia e Consultoria Ltda (1991). O mesmo, mostrou-se adequado para fins de simulações de fluxo bidimensionais em locais onde as informações são incipientes. Os valores dos parâmetros hidrodinâmicos do aquífero foram obtidos em consequência do aferimento do modelo de fluxo, e a velocidade média, linear, de propagação de fluxo no aquífero,.de acordo com os parâmetros aferidos, é da ordem de 0.672 m/dia com direção NW — SE, sentido SE. A propagação das plumas dos contaminantes acima mencionados, foram geradas uti1izando—se o modelo de transporte embasado no método explícito das diferenças finitas como dado por Kinzelbach, (1986). As concentrações tomadas como referência para a calibração do modelo, foram aquelas amostradas em poços de monitoramentos e de produção (Paranaguá, 1991) e analisadas pelo laboratório americano Industrial and Environmental Analyses, Inc - IEA. Apesar da simplicidade do modelo, principalmente por tratar o meio como homogéneo e isotrópico e processar os compostos como conservativos ou seja, substâncias químicas não reagentes, a pluma para o 1,2 — DCP apresentou um resultado que confirma a veracidade do modelo. Já as plumas par*, o 1,2 — DCE , para o 1,2,3 — TCP e para os organos totais ( projetada com base nas análises do laboratório da Companhia Alagoas Industrial — CINAL, pois o IEA não os dosou), mostraram-se confiáveis. / This dissertation presents the resulta of the research done on contaraination of "Aquífero Barreiras" by organo-chlorides, in the Pole- Choloro-chemicais of Alagoas - PCA. The cheraical substances involved in the process that are Products which pose strong toxiclty, affected the quality of the aquifer in question, creating .significant environaental impact as a grave problem. The more important of these contaminants were the 1,2 Di-chloroehtane (1,2 - DCE), 1,2 D i-chioropropane (1,2 DCP) and 1,2,3 Tri-chloropropane (1,2,3 - TCE), which appeared in greater concentrations, because of which the present investigation was attempted. The Aquifer "Barreiras", within the PCA area has a nean depth of 20 m, lithoiogicaliy represented by a packet of sandysilt stratum, sandwitched by discontinuous clayey material, thus characterizing on the whole as a freatic aquifer. The "flow raodel" adopted, based on the finite d i fferenr.es method - the Algorithm of IAOI (Kinzelback, 1986), utilized data extracted from the reports of an enterprize by naie "Paranaguá' Eng inssr ing and Cônsultants Ltd. ÍÍ99Í). The cited raodel was found to be adequate for the purpose of simulating the two-dímentional flows in places where data is available. Values of hydrodynamic parameters of the aquifer were obtaíned frora the resulto of flow model and the raean linear propagation velocity in the aquifer, based on the input values, was of the order of 0.672 m/day, in the N.W. - S.E. frora S.E. direction. PIume propagations for the above mentioned comtaminants were geenerated utilizing the "transport model", based on the explicit finite difference method as suggested by Kinzelbach (í?G6). Concentrations taken as reference for the model calibration were those values registered in the product ion and observation wells (Paranaguá, 1991), the results of which were analyzed by an American laboratory by name Industrial and Environmental Anaíyses, Inc. (I.E.A.). Dispite the simplicity of the model, principally considering the porous media as homogeneous and isotropic, and considering the chemicals as conservative, i.e., chemical substances that do not react with water, the plurne for 1,2 - DCP showed results that confirmed the varacity of the model. The plumes for 1,2 - DCE and 1,2,3 - TCP and for total organo-chlorides that are projected on the basis of analysis of the laboratory of Alagoas Industrial Co. -CINAL, also showed sufficiently reliable results.

No description available.

Bibliographische Beschreibung und Referat Frosch, W. Synthese und Reaktionsverhalten Bis(alkinyl)-Metallocen-stabilisierter monomerer Organo-Kupfer(I)-Verbindungen Technische Universität Chemnitz, Fakultät für Naturwissenschaften, Dissertation, 2001, 103 Seiten. In der vorliegenden Arbeit werden Synthese und Reaktionsverhalten von hetero-metallischen Ti(IV)-Cu(I)-Komplexen der Art {[Ti](CCR1)2}CuX {[Ti] = (h5-C5H4SiMe3)2Ti; R1 = einfach gebundener organischer Rest; X = anorganischer, organischer oder metallorganischer Rest} beschrieben. Diese Verbindungen können zwei bis fünf Übergangsmetall-Atome enthalten, welche durch verschiedene Komplex-Liganden und auf unterschiedliche Bindungsweise miteinander verknüpft sind. Zentrale Bausteine der in dieser Arbeit untersuchten Komplexe sind die metallorganischen pi-Pinzetten [Ti](CCR1)2 und der monomere Kupfer(I)-Methyl- Komplex {[Ti](CCR1)2}CuCH3. Letzterer kann in vielfältiger Weise zur Synthese verschiedener bis(h2-alkin)-stabilisierter Kupfer(I)-Verbindungen verwendet werden, welche im besonderen Interesse der vorliegenden Untersuchungen standen. Des Weiteren war das Augenmerk auf das Reaktionsverhalten von [Ti](CCR1)2 gegenüber ÜM-Komplexen von Metallen der Gruppe 12 des Periodensystems der Elemente in verschiedenen Oxidationsstufen gerichtet. Die im Rahmen dieser Arbeit durchgeführten Untersuchungen lassen sich dabei in vier Schwerpunkte gliedern: 1) Mehrfach Carboxylat-funktionalisierte Ti(IV)-Cu(I)-Komplexe: Synthese, Fest-körperstruktur und Reaktionsverhalten. 2) Reaktion von Bis(alkinyl)-Titanocenen mit Metall-Verbindungen der Gruppe 10-12 des Periodensystems der Elemente. 3) Donor-funktionalisierte Bis(alkinyl)-Titanocene und deren Reaktionsverhalten. 4) Monomeres Kupfer(I)-Methyl als synthetisches Werkzeug: Synthese einer breiten Palette unterschiedlicher Kupfer(I)-Systeme. Stichworte: metallorganisch, heterometallisch, pi-Systeme, Metallocene, Alkine, Bis(alkinyl)-Titanocene, metallorganische pi-Pinzetten, Koordinationsverbindungen, Kupfer(I), monomere Kupfer(I)-Organyle.

Endlosfaserverstärkte Thermoplaste werden oftmals als imprägnierte und konsolidierte Halbzeuge angeboten. Solche thermoplastischen Prepregs werden üblicherweise als Organobleche bezeichnet. Die thermoplastische Matrix ermöglicht unter anderem die Warmformbarkeit und Schweißbarkeit von Organoblechen. Organobleche sind, durch die ausschließliche Möglichkeit sie mittels Thermoformen umzuformen, in ihrer Formgebung auf halbschalige Strukturen beschränkt, welche begrenzte Torsions-, Verwindungs- und Beulsteifigkeiten aufweisen. Um die Steifigkeiten dieser schalenförmigen, offenen Bauteile zu erhöhen, können z. B. versteifende Rippen oder Verstärkungssegmente eingebracht werden. Aufgrund des Thermoformprozesses sind mit Organoblechen, verglichen mit duroplastischen Systemen, jedoch nur kleine und einfache Bauteilgeometrien realisierbar. Um neben der Steifigkeitserhöhung auch größere und komplexere Bauteile herzustellen, können die schalenförmigen Organobleche während des Umformvorgangs gefügt werden. Auf diese Weise werden Hohlkörper in Doppelhutprofilform gefertigt. So werden, auch ohne Einbringung von Rippen o. ä., hohe Bauteilsteifigkeiten erreicht. Die Doppelhutprofilform hat jedoch eine nicht optimale Nutzung der Faserverstärkung über die Fügeebene hinweg zur Folge, da die Fasern von der Belastungsrichtung abweichend umgelenkt werden. Im vorliegenden Beitrag wird daher das überlappende Infrarotschweißen von Organoblechen behandelt, was eine Faserverstärkung über die Fügeebene hinweg ermöglicht. Die Prozess- und Werkstoffeinflüsse auf die Verbindungseigenschaften werden beschrieben und Möglichkeiten zur Optimierung der Schweißnahteigenschaften dargestellt. Des Weiteren werden Optimierungskriterien für überlappende Infrarotschweißungen an den untersuchten Organoblechen festgelegt. Die im Verlauf der Forschungsarbeiten umzusetzenden Verfahrensvarianten zur Herstellung von Hohlkörperbauteilen aus Organblechen werden zudem vorgestellt.