The intercalation of surfactant anions, namely sodium dodecyl sulphate, sodium benzene sulphonate and lauric acid, into commercial layered double hydroxides (LDH-CO3) with approximate composition [Mg0.654AI0.346 (OH)2](CO3)0.173.0.5H2O] was explored. LDH-CO3 is commercially available in bulk form owing to its large scale applications as a PVC stabiliser and acid scavenger in polyolefins. It is therefore of interest to investigate intercalation methods using LDH-CO3 as starting material. The intercalation method used was compared with the pre existing procedures, for instance the co-precipitation, ion exchange and regeneration methods. Due to the tenacity with which the carbonate ion is held in LDH-CO3, direct ion exchange is an intricate matter. Hence, in the regeneration method the carbonate ion is removed by thermal treatment and the LDH-surfactant is obtained by reaction of the LDH and surfactant in an aqueous medium. Nevertheless, the resulting products are impure and poorly crystallised, and only partial intercalation is achieved. The underlying principle of the current method is protonation of the carbonate anion to a monovalent anion that is easily exchanged with surfactant anions. Improved results were obtained when water-soluble organic acids were used, the most suitable being lower aliphatic carboxylic acids, e.g. acetic, butyric and hexanoic acid. In contrast, higher linear aliphatic carboxylic acids are preferentially intercalated to the anionic surfactants. In both cases the carboxylic acids are assumed to assist intercalation by facilitating the elimination of the carbonate ions present in the anionic clay galleries. X-ray diffraction analysis, thermal analysis and infrared spectroscopy confirmed the monolayer intercalation of LDH-dodecyl sulphate and LDH-dodecylbenzene sulphonate. In contrast, LDH-laurate featured a bilayer structure. / Dissertation (MSc)--University of Pretoria, 2009. / Chemistry / unrestricted

The objective of this work is to advance the mechanistic understanding of cathodic electrocoating. These efforts are focused on the initial processes responsible for deposition, which are examined through direct experimentation and simulation. Electrocoating is a global industrial process providing a corrosive resistant base paint to automobile bodies. Presently, empirical models are used to model coating thickness; these models tend to overpredict deposition in occluded areas. Convection is implemented to study the behavior of adhered surface H2 bubbles on the substrate surfaces. The impact of surface H2 bubbles and early e-coat deposition on the local current density is studied using simulations. Results show an increased local current density around surface H2 bubbles and early e-coat deposition influences film growth. When surface H2 bubbles are displaced before sufficient e-coat is deposited the lack of increased local current density slows deposition. However, when sufficient e-coat is deposited and then surface H2 bubbles are displaced, the induction period is unaffected since the early deposition is sufficient to keep the local current density high enough to drive deposition. Solution factors are qualitatively studied using a diluted e-coat dispersion and a anionic exchange membrane cell. Experiments demonstrate a visual change in the solution near the cathode and indicates a coagulation of micelles in this region. Experiments also demonstrate a rise in pH is associated with the induction time, but is not necessary for e-coat deposition. Film resistance is used to understand film growth and film morphology during industrial electrocoating. Interruption experiments demonstrate H2 bubbles may influence film resistance. Film density and resistivity results cannot be completely explained with understood physics, underlining the importance of future resistance studies. These results provide an increased understanding of fundamental processes responsible for initial deposition, which is the foundation needed for advanced physics-based models of the electrocoating process.

No description available.

No description available.

Grafting polymeric chains on the surface of nanoparticles is an effective way to enhance particle-matrix interaction and their homogeneous dispersion within the matrix, leading to improved physical and mechanical properties. However, current methods for grafting polymeric chains onto nanoparticles have not produced well-defined polymers with high grafting density. Here, we employed anionic polymerization high vacuum techniques to synthesize in-situ grafted silica nanoparticles with either polystyrene (PS), polystyrene-b-polyisoprene (PS-b-PI) or 3- miktoarm star polymers (3-µ stars polymer) ((PS)2PS, (PS)2PI, and (PS)2PI-b-PS) by hydrolysis/condensation of ω-tetraethyl orthosilicate (TEOS) of PS, PS-b-PI and 3-µ star polymers. The molecular characteristics of the precursors PS-TEOS, PS-b-PI-TEOS, and 3-µ star polymer-TEOS were determined by 1H NMR, SEC, and MALDI-ToF. The synthesis of PS (PS@SiO2 NPs), PS-b-PI (PS-b-PI@SiO2 NPs), and 3-µ star polymer ((PS)2PS)@SiO2, (PS)2PI)@SiO2, and (PS)2PI-b-PS@SiO2 NPs) nanoparticles was verified by FT-IR, 29Si solid-state NMR, TEM, TGA, and DLS. Blends of PS@SiO2 with commercially available PS and PS-b-PI@SiO2 and 3-µ star polymer@SiO2 with anionically synthesized thermoplastic elastomer (PS-b-PI-b-PS), were obtained either in melt by extrusion or in solution by evaporation. The role of polymer@SiO2 on the mechanical and morphological properties was examined by tensile testing and SEM. In the fifth chapter, a high grafting density of polymer on the surface of SiO2 NPs approach that may also be employed in industry was presented. TEOS will be present in every repeating unit in the second block rather than simply the end group as it was in the first three chapters. First, anionic polymerization of PS functionalized with bromide group to utilize as a macroinitioter. Then, the macroinitioter (PS-Br) will initiate the polymerization of VTES (vinyltriethoxysilyl), ATMS (alyltrimethoxysilyl), and SETMS (styrene ethyltrimethoxysilyl) via atom transfer radical polymerization (ATRP) to form PS-b-PVTES, PS-b-PATMS, and PS-b-SETMS. SEC, 1H NMR, FT-IR, 29Si solid-state NMR, TEM, and DLS were used to confirmed copolymer grafting on SiO2 NPs. Lastly, a tensile test was used to study the mechanical properties of the nanocomposite. The proposed method controls the molecular weight, chemical composition, particle size and grafting density of nanoparticles and effectively improves the mechanical characteristics of the two families of PS-based nanocomposites.

[ES] El fósforo es inherente al mantenimiento de la vida y desempeña un papel fundamental en la producción de alimentos. La inminente escasez de rocas fosfóricas, principal materia prima para la producción de fertilizantes a base de fósforo ha impulsado la investigación sobre la recuperación de este nutriente a partir de fuentes alternativas, como las aguas residuales municipales. En un estudio reciente, fue posible concentrar y recuperar fosfatos de una solución que simulaba aguas residuales municipales mediante electrodiálisis, además de promover la separación de fosfatos de los aniones coexistentes. Sin embargo, este proceso de separación comprometió la estructura de la membrana aniónica. Por lo tanto, el objetivo de este trabajo fue establecer las condiciones adecuadas para recuperar fosfatos de una solución con bajo contenido de este nutriente. Se realizaron experimentos de electrodiálisis bajo intenso campo eléctrico utilizando dos membranas aniónicas diferentes, una de origen chino (IONSEP-HC-A) y otra checa (AMHPP, resistente a medios alcalinos), caracterizándolas antes y después de los ensayos. Además, se estudiaron las reacciones químicas que acompañan al transporte de fosfatos a través de membranas aniónicas mediante voltamperometría lineal, cronopotenciometría y espectroscopia de impedancia electroquímica. Los resultados de las pruebas de electrodiálisis indican la posibilidad de separación de iones de fosfato utilizando la membrana IONSEP-HC-A, condición que no se logra con la membrana AMHPP. Mediante espectros FTIR se observó que la aplicación de campos eléctricos intensos provocó la transformación parcial de los grupos funcionales de ambas membranas. Sin embargo, además de esto, se notó la degradación de la malla estructural de la membrana china. Además, las imágenes SEM indicaron la formación de cavidades en la superficie de la membrana IONSEP-HC-A, lo que no se observó en la membrana AMHPP. A través de estas imágenes también se observó que la superficie de la membrana AMHPP tiene una mayor área conductora, lo que puede facilitar la formación de vórtices electroconvectivos, mientras que la distribución de grupos funcionales en la membrana IONSEP-HC-A facilitaría la disociación del agua. Estas suposiciones se confirman mediante espectros de impedancia y curvas cronopotenciométricas. Para la membrana AMHPP, las curvas cronopotenciométricas atestiguan que la electroconvección es el mecanismo predominante de transferencia de masa, a pesar de la presencia de arcos de Gerischer que indican la ocurrencia de reacciones químicas en la capa límite de difusión. En cuanto a la membrana IONSEP-HC-A, los resultados muestran el predominio de la disociación del agua, lo que dificulta el paso de los iones fosfato a través de la membrana y permite su separación. / [CA] El fòsfor és inherent al manteniment de la vida i exerceix un paper fonamental en la producció d'aliments. La imminent escassetat de roques fosfòriques, principal matèria primera per a la producció de fertilitzants a base de fòsfor ha impulsat la investigació sobre la recuperació d'aquest nutrient a partir de fonts alternatives, com les aigües residuals municipals. En un estudi recent, va ser possible concentrar i recuperar fosfats d'una solució que simulava aigües residuals municipals mitjançant electrodiálisis, a més de promoure la separació de fosfats dels anions coexistents. No obstant això, aquest procés de separació va comprometre l'estructura de la membrana aniònica. Per tant, l'objectiu d'aquest treball va ser establir les condicions adequades per a recuperar fosfats d'una solució amb baix contingut d'aquest nutrient. Es van realitzar experiments de electrodiálisis baix intens camp elèctric utilitzant dues membranes aniòniques diferents, una d'origen xinés (IONSEP-HC-A) i una altra txeca (AMHPP, resistent a mitjans alcalins), caracteritzant-les abans i després dels assajos. A més, es van estudiar les reaccions químiques que acompanyen al transport de fosfats a través de membranes aniòniques mitjançant voltamperometria lineal, cronopotenciometría i espectroscòpia d'impedància electroquímica. Els resultats de les proves de electrodiálisis indiquen la possibilitat de separació d'ions de fosfat utilitzant la membrana IONSEP-HC-A, condició que no s'aconsegueix amb la membrana AMHPP. Mitjançant espectres FTIR es va observar que l'aplicació de camps elèctrics intensos va provocar la transformació parcial dels grups funcionals de totes dues membranes. Tanmateix, a més d'això, es va notar la degradació de la malla estructural de la membrana xinesa. A més, les imatges SEM van indicar la formació de cavitats en la superfície de la membrana IONSEP-HC-A, la qual cosa no es va observar en la membrana AMHPP. A través d'aquestes imatges també es va observar que la superfície de la membrana AMHPP té una major àrea conductora, la qual cosa pot facilitar la formació de vòrtexs electroconvectivos, mentre que la distribució de grups funcionals en la membrana IONSEP-HC-A facilitaria la dissociació de l'aigua. Aquestes suposicions es confirmen mitjançant espectres d'impedància i corbes cronopotenciométricas. Per a la membrana AMHPP, les corbes cronopotenciométricas testifiquen que la electroconvección és el mecanisme predominant de transferència de massa, malgrat la presència d'arcs de Gerischer que indiquen l'ocurrència de reaccions químiques en la capa límit de difusió. Quant a la membrana IONSEP-HC-A, els resultats mostren el predomini de la dissociació de l'aigua, la qual cosa dificulta el pas dels ions fosfate a través de la membrana i permet la seua separació. / [EN] Phosphorus is inherent in maintaining life and plays a key role in food production. The imminent scarcity of phosphate rocks, the main raw material for the production of phosphorus-based fertilizers has boosted research on the recovery of this nutrient from alternative sources, such as municipal wastewater. In a recent study, it was possible to concentrate and recover phosphates from a solution simulating municipal wastewater through electrodialysis, as well as promoting the separation of phosphates from existing anions. However, this separation process compromised the structure of the anion-exchange membrane. Therefore, the objective of this work was to establish adequate conditions to recover phosphates from a low phosphate-containing solution. Electrodialysis experiments were carried out under intense electric field using two different anion-exchange membranes, one of Chinese origin (IONSEP-HC-A) and the other Czech (AMHPP, alkali-resistant), characterizing them before and after the tests. Furthermore, chemical reactions that accompany the transport of phosphates through anion-exchange membranes were studied using linear voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The electrodialysis results indicate the possibility of phosphates separation using the IONSEP-HC-A membrane, a condition not achieved with the AMHPP membrane. Through FTIR spectra, it was observed that the application of intense electric fields caused the partial transformation of the functional groups of both membranes. However, in addition to this, the degradation of the structural mesh of the Chinese membrane was noted. Furthermore, SEM images indicated the formation of cavities on the surface of the IONSEP-HC-A membrane, which was not observed for the AMHPP membrane. Through these images, it was also observed that the surface of the AMHPP membrane has a larger conductive area, which may facilitate the formation of electroconvective vortices, while the distribution of functional groups in the IONSEP-HC-A membrane would facilitate the dissociation of water. These assumptions are confirmed by means of impedance spectra and chronopotentiometric curves. For the AMHPP membrane, chronopotentiometric curves attest to electroconvection as the predominant mass transfer mechanism, despite the presence of Gerischer arcs indicating the occurrence of chemical reactions in the diffusion boundary layer. As for the IONSEP-HC-A membrane, the predominance of water dissociation was noted, making it difficult for phosphate ions to pass through the membrane and allowing their separation. / [PT] O fósforo é inerente à manutenção da vida e exerce um papel fundamental na produção de alimentos. A iminente escassez de rochas fosfatadas, principal matéria-prima para produção de fertilizantes a base de fósforo tem impulsionado pesquisas sobre a recuperação desse nutriente de fontes alternativas, como as águas residuárias municipais. Em estudo recente, foi possível concentrar e recuperar fosfatos de uma solução simulando uma água residuária municipal através da eletrodiálise, bem como promover a separação de fosfatos de ânions coexistentes. Entretanto, esse processo de separação comprometeu a estrutura da membrana aniônica. Assim sendo, o objetivo desse trabalho foi estabelecer condições adequadas para recuperar fosfatos de uma solução com baixo teor desse nutriente. Foram realizados experimentos de eletrodiálise mediante intenso campo elétrico utilizando diferentes duas membranas aniônicas, uma de origem chinesa (IONSEP-HC-A) e outra tcheca (AMHPP, resistente a meios alcalinos), caracterizando-as antes e após os ensaios. Ainda, foram estudadas as reações químicas que acompanham o transporte de fosfatos por membranas aniônicas empregando a voltametria linear, cronopotenciometria e a espectroscopia de impedância eletroquímica. Os resultados dos ensaios de eletrodiálise indicam a possibilidade de separação de íons fosfato usando a membrana IONSEP-HC-A, condição não atingida com a membrana AMHPP. Por meio de espectros de FTIR, observou-se que a aplicação de intensos campos elétricos ocasionou a transformação parcial dos grupos funcionais de ambas as membranas. Porém, adicionalmente a isso, notou-se a degradação da malha estrutural da membrana chinesa. Ainda, imagens de MEV indicaram a formação de cavidades na superfície da membrana IONSEP-HC-A, o que não foi observado para a membrana AMHPP. Por meio dessas imagens, observou-se também que a superfície da membrana AMHPP possui maior área condutora, podendo facilitar a formação de vórtices eletroconvectivos, enquanto a distribuição dos grupos funcionais na membrana IONSEP-HC-A facilitaria a dissociação de água. Essas suposições são confirmadas por meio de espectros de impedância e curvas cronopotenciométricas. Para a membrana AMHPP, curvas cronopotenciométricas atestam a eletroconvecção como mecanismo de transferência de massa predominante, apesar da presença de arcos de Gerischer indicando a ocorrência de reações químicas na camada limite de difusão. Já para a membrana IONSEP-HC- A, os resultados evidenciam a predominância da dissociação de água, dificultando a passagem de íons fosfato através da membrana e permitindo a sua separação. / Rotta, EH. (2023). Caracterização de membranas aniônicas e avaliação do transporte de íons fosfato em um sistema de eletrodiálise [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/191741

Yes / UV/vis absorption titrations have been used to investigate the formation of H-bonded complexes between anionic H-bond acceptors (HBAs) and neutral H-bond donors (HBDs) in organic solvents. Complexes formed by three different HBDs with 15 different anions were studied in chloroform and in acetonitrile. The data were used to determine self-consistent HBA parameters (β) for chloride, bromide, iodide, phosphate diester, acetate, benzoate, perrhenate, nitrate, triflimide, perchlorate, hexafluorophosphate, hydrogen sulfate, methyl sulfonate, triflate, and perfluorobutyl sulfonate. The results demonstrate the transferability of H-bond parameters for anions between different solvents and different HBD partners, allowing reliable prediction of anion recognition properties in other scenarios. Carboxylates are the strongest HBAs studied, with β parameters (≈ 15) that are significantly higher than those of neutral organic HBAs, and the non-coordinating anion hexafluorophosphate is the weakest acceptor, with a β parameter comparable to that of pyridine. The effects of ion pairing with the counter-cation were found to be negligible, provided small polar cations were avoided in the less polar solvent (chloroform). There is no correlation between the H-bonding properties of the anions and the pKa values of the conjugate acids. / Engineering and Physical Sciences Research Council (EPSRC).

Tesis por compendio / [EN] The doctoral thesis presented under the title "Hybrid inorganic-organic materials for the optical recognition of neutral and anionic species" has had as its main objective the synthesis and characterization of organic-inorganic hybrid materials based on the combination of the principles of Supramolecular Chemistry and Materials Science. Recent studies confirm that cooperation between these two areas of Chemistry allow the simulation of what natural living beings have been doing for millions of years in a natural way. At cellular level, many vital functions are related to the ability of a particular receptor to recognize a particular species, giving a specific answer. But what is more interesting is that in living organisms, most of these systems do not exist as dissolved molecules, but are bounded to a (bio)organic skeleton with more or less flexibility. When we imitated these systems bearing in mind the supramolecular and analytical chemistry, we find that we need a sensory molecule able to join with the specie that we want to detect and at the same time, this union must produce a change in its physico-chemical properties giving as a result a signal. But moreover, if we take advantatge of the fact that siliceous nanostructured materials present a high physical and chemical stability and that they have cavities where the sensor system can be incorporated into, we have the synthetic hybrid organic-inorganic combination similar to the natural one. In order to develop this idea, we have used sensor systems widely studied in molecular recognition processes in aqueous media and we have applied them to the inorganic-organic hydrid materials. Therefore, the present work thesis has been structured in two parts: on the one hand, the synthesis and characterization of the functionalized inorganic porous solid materials by the study and detection of amines using the "chemodosimeter" approach. On the other hand, we have made the synthesis and characterization of the organic functionalized inorganic porous solid materials for the study and detection of anionic species through the displacement assays approach. / [ES] La tesis doctoral que se presenta bajo el título "Hybrid inorganic-organic materials for the optical recognition of neutral and anionic species" ha tenido como objetivo principal la síntesis y caracterización de materiales híbridos orgánico-inorgànicos basados en la combinación de los principios de la Química Supramolecular y la Ciencia de los Materiales. Recientes estudios corroboran que la cooperación entre estas dos áreas de la Química permite simular lo que ya hace millones de años realizan de forma natural los organismos vivos. A nivel celular, muchas de las funciones vitales están relacionadas con la habilidad de un receptor concreto para reconocer una determinada especie, dando una respuesta específica. Pero lo que resulta más interesante, es que en los organismos vivos, la mayoría de estos sistemas no existen en forma de moléculas disueltas, sino que están unidos con mayor o menor flexibilidad a un esqueleto bio(in)orgánico. Cuando imitamos estos sistemas teniendo en cuenta la química supramolecular y analítica, nos encontramos que necesitamos de una molécula indicadora que sea capaz de unirse a la especie que queremos detectar y que a su vez, esta unión produzca un cambio en las propiedades físico-químicas de la entidad para producir una señal. Pero además, si aprovechamos el hecho de que los materiales silíceos nanoestructurados presentan una alta estabilidad física y química y que proporcionan cavidades donde alojar al sistema sensor, tenemos la combinación híbrida orgánico-inorgánico sintética similar a la natural. Con el objetivo de desarrollar esta idea, hemos utilizado sistemas sensores ampliamente estudiados en procedimientos de reconocimiento molecular en disolución acuosa y los hemos aplicado a los materiales híbridos orgánico-inorgànicos. De esta manera, el trabajo de tesis se ha estructurado en dos partes: por una parte, la síntesis y caracterización de materiales sólidos inorgánicos porosos funcionalizados para el estudio y detección de aminas utilizando el procedimiento de "dosímetro químico", y en una segunda parte, se ha llevado a cabo la síntesis y caracterización de sólidos inorgánicos porosos funcionalizados para el estudio y detección de especies aniónicas mediante el procedimiento de "ensayos por desplazamiento". / [CA] La tesis doctoral que es presenta sota el títol "Hybrid inorganic-organic materials for the optical recognition of neutral and anionic species" ha tingut com objectiu principal la síntesi i caracterització de materials híbrids orgànic-inorgànics basats en la combinació dels principis de la Química Supramolecular i la Ciència dels Materials. Estudis recents corroboren que la cooperació entre aquestes dues àrees de la Química permet simular el que ja fa milions d'anys realitzen de forma natural els organismes vius. A nivell cel·lular, moltes de les funcions vitals estan relacionades amb l'habilitat d'un receptor concret per a reconèixer una espècie determinada, donant una resposta específica. Però el que és més interessant, és que als organismes vius, la majoria d'aquests sistemes no existeixen en forma de molècules dissoltes, sinó que estan units amb major o menor flexibilitat a un esquelet bio(in)orgànic. Quan imitem aquests sistemes tenint en compte la química supramolecular i analítica, ens trobem que necessitem d'una molècula indicadora que sigui capaç d'unir-se a l'espècie que volem detectar i que alhora, aquesta unió produeixi un canvi en les propietats fisico-químiques de l'entitat per produir una senyal. Però a més, si aprofitem el fet que els materials silícics nanoestructurats presenten una alta estabilitat física i química i que proporcionen cavitats on es pot allotjar el sistema sensor, tenim la combinació híbrida orgànica-inorgànica sintètica semblant a la natural. Per tal de desenvolupar aquesta idea, hem utilitzat sistemes sensors ampliament estudiats en procediments de reconeixement molecular en dissolució aquosa i els hem aplicat als materials híbrids orgànic-inorgànics. Així el present treball de Tesis s'ha estructurat en dues parts: per una banda, la síntesis i caracterització de materials sòlids inorgànics porosos funcionalitzats per l'estudi i detecció d'amines utilitzant el procediment de "dosímetre químic", i en una segona part, s'ha realitzat la síntesis i caracterització de sòlids inorgànics porosos funcionalitzats per a l'estudi i detecció d'espècies aniòniques mitjançant el procediment "d'assajos per desplaçament". / Comes Navarro, M. (2016). Hybrid inorganic-organic materials for the optical recognition of neutral and anionic species [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/62153 / Compendio

The present PhD thesis deals with the synthesis and characterization of functionalized ferrocenes with up to four aldehyde and vinyl groups and their usage as monomers to produce novel ferrocene-based oligomers with conjugated backbones via ADMET (acyclic diene metathesis) and HWE (Horner-Wadsworth-Emmons) reaction protocols. In addition, ferrocene-containing polymers (linear, cross-linked and co-polymers) with aliphatic backbones generated by anionic bulk and solution polymerization routes, and their electrochemistry behaviors were studied. The main aspects of this work lies in the enhancement of the electrical properties of the ferrocene-based materials (oligomers or polymers) by varying the polymer backbone, providing multi-functionalities for cross-linking and co-polymerization processes and thereby increasing the molecular weight of the products, furthermore, the application as electro-active materials, especially for the charge storage purposes is discussed. High monomer consumption, relatively high molar mass as well as longer chains were achieved by bulk protocol. Electrochemical measurements (CV) reveals that formyl-ferrocenes bearing more than two formyl functionalities are very electron poor materials and easily decomposes upon oxidation. Reducing the measurement temperature and the usage of [NnBu4][B(C6F5)4] as electrolyte allowed for reliable behavior. A linear correlation between the redox potential and the number of the formyl functionalities was found. Multicyclic measurements showed that ferrocenyl / ferrocenium redox couples in the polymeric materials are stable at least up to 100 cycles. The spectro-electrochemical studies show that the conjugated materials (oligomers) have electron transfer interactions (IVCT) through the chains, while the aliphatic backbone between the ferrocenyl units (poly vinylferrocene materials) hindered the metal-metal coupling along the chain and only a ligand-to-metal charge transfer excitation could be observed. / Die vorliegende Doktorarbeit beschäftigt sich mit Synthese und Charakterisierung von funktionalisierten Ferrocenen mit bis zu vier Aldehyd- und Vinylgruppen und ihrer Verwendung als Monomere für neuartige ferrocenbasierte Oligomere mit konjugiertem Rückgrat unter ADMET (acyclic diene metathesis) und HWE- (Horner-Wadsworth-Emmons) Reaktionsbedingungen. Zusätzlich wurden ferrocenhaltige Polymere mit einem aliphatischen Rückgrat durch Polymerisation mit und ohne Lösemittel hergestellt und ihr elektrochemisches Verhalten untersucht. Das Hauptaugenmerk dieser Arbeit liegt in der Optimierung der elektrochemischen Eigenschaften der ferrocenbasierten Materialien (Oligomere oder Polymere) durch Variation des Polymerrückgrats, welche zahlreiche funktionelle Gruppen für die vernetzte Polymerisation und die Co-Polymerisation liefert. Durch diesen Prozess wird das molekulare Gewicht erhöht. Zusätzlich wird die Verwendung als elektroaktive Materialien insbesondere für die Energiespeichertechnik diskutiert. Durch lösungsmittelfreie Reaktionsbedingungen wurden ein hoher Monomerumsatz, relativ hohe molare Massen und zugleich längere Polymerketten erzielt. Elektrochemische Messungen (CV) zeigten, dass Ferrocenmoleküle mit mehr als zwei Formylgruppen die Elektronendichte an der Ferrocenyleinheit verringern und bei Oxidation leicht zersetzt werden. Erniedrigung der Messtemperatur und die Verwendung des nur schwach koordinierenden Leitsalzes [NnBu4][B(C6F5)4] führten zu aussagekräftigen Ergebnissen. Weiterhin konnte ein linearer Zusammenhang zwischen dem Redoxpotential und der Anzahl der Formyleinheiten aufgezeigt werden. Mutlizyklische Messungen bestätigten, dass das Ferrocen / Ferrocenium-Redoxpaar mindestens 100 Zyklen stabil ist. Mittels spektroelectrochemisches Messungen konnte gezeigt werden, dass konjungierte (oligomere) Verbindungen eine elektronische Wechselwirkung (IVCT) aufweisen, während aliphatische Rückgrade eine Wechselwirkung zwischen Ferrocen / Ferrocenium (polyvinylferrocenbasierte Materialien) verhindern und nur ein LMCT Übergang (Ligand zu Metall Charge-Transfer) beobachtet werden kann.

This thesis describes the reactivity of Zintl ions of groups 14 [E₉]^4– (E = Ge and Sn)and 15 [E'₇]^3– (E' = P and As) towards a number or transition, post-transition and main group reagents. The synthesis and characterisation of the resulting novel cluster anions is described herein. Coordination compounds of group 14 Zintl ions were synthesised when K₄Ge₉ was reacted with Zn[N(SiMe₃)₂]₂ to give the simple coordination compound [Ge₉ZnN(SiMe₃)₂]^3–. The heavier analogue K₄Sn₉ reacts with the same metal precursor to give the paramagnetic species [Sn₉ZnNSiMe₃]^3– where a trimethylsilyl group has been lost. K₄Ge₉ reacts with [Ru(COD)(η³-CH₂C(CH₃)CH₂)₂] to form the paramagnetic endohedral compound [Ru@Ge₁₂]^3– and with [Co(PEt₂Ph)₂(mes)₂] to form the prolate endohedral compound [Co₂@Ge₁₆]^4–, which has two metal centres encapsulated inside the sixteen atom germanium cage. Regarding group 15 Zintl ion reactivity, the reactions between pyridine solutions of [HP₇]^2– and E[N(SiMe₃)₂]₂ (E = Ge, Sn and Pb) have been found to yield coordination compounds of the type [P7E(N(SiMe3)2]2–. The germanium containing species [P₇GeN(SiMe₃)₂]^2– quickly decomposes at room temperature to give rise to the thermodynamic product [(P₇)₂Ge₂N(SiMe₃)₂]^3–, a process that involves the loss of an amide moiety. Activation products were also synthesised from the reaction of [E'₇]^3– with varying stoichiometries of VCp₂. The reaction with 0.7 equivalents of VCp₂ yields the sandwich complexes [CpV(η⁵-E'₅)]^n– (E' = P: n = 1; E' = As, n = 1 and 2) whereas with 2.5 equivalents the products are the triple-decker sandwich complexes [(CpV)₂(η^x-E'_x)]– (E' = P: x = 6; E' = As: x = 5).