The needs for sustainable energy generation, but also a sustainable chemistry display the basic motivation of the current thesis. By different single investigated cases, which are all related to the element carbon, the work can be devided into two major topics. At first, the sustainable synthesis of “useful” carbon materials employing the process of hydrothermal carbonisation (HC) is described. In the second part, the synthesis of heteroatom - containing carbon materials for electrochemical and fuel cell applications employing ionic liquid precursors is presented. On base of a thorough review of the literature on hydrothermolysis and hydrothermal carbonisation of sugars in addition to the chemistry of hydroxymethylfurfural, mechanistic considerations of the formation of hydrothermal carbon are proposed. On the base of these reaction schemes, the mineral borax, is introduced as an additive for the hydrothermal carbonisation of glucose. It was found to be a highly active catalyst, resulting in decreased reaction times and increased carbon yields. The chemical impact of borax, in the following is exploited for the modification of the micro- and nanostructure of hydrothermal carbon. From the borax - mediated aggregation of those primary species, widely applicable, low density, pure hydrothermal carbon aerogels with high porosities and specific surface areas are produced. To conclude the first section of the thesis, a short series of experiments is carried out, for the purpose of demonstrating the applicability of the HC model to “real” biowaste i.e. watermelon waste as feedstock for the production of useful materials. In part two cyano - containing ionic liquids are employed as precursors for the synthesis of high - performance, heteroatom - containing carbon materials. By varying the ionic liquid precursor and the carbonisation conditions, it was possible to design highly active non - metal electrocatalyst for the reduction of oxygen. In the direct reduction of oxygen to water (like used in polymer electrolyte fuel cells), compared to commercial platinum catalysts, astonishing activities are observed. In another example the selective and very cost efficient electrochemical synthesis of hydrogen peroxide is presented. In a last example the synthesis of graphitic boron carbon nitrides from the ionic liquid 1 - Ethyl - 3 - methylimidazolium - tetracyanoborate is investigated in detail. Due to the employment of unreactive salts as a new tool to generate high surface area these materials were first time shown to be another class of non - precious metal oxygen reduction electrocatalyst. / Die Notwendigkeit einer nachhaltigen Energiewirtschaft, sowie der nachhaltigen Chemie stellen die Motivation der vorgelegten Arbeit. Auf Grundlage separater Untersuchungen, die jeweils in engem Bezug zum Element Kohlenstoff stehen, kann die Arbeit in zwei Themenfelder geordnet werden. Der erste Teil behandelt die nachhaltige Herstellung nützlicher Kohlenmaterialien mit Hilfe des Verfahrens der hydrothermalen Carbonisierung. Im zweiten Teil wird die Synthese von Bor und Stickstoff angereicherten Kohlen aus ionischen Flüssigkeiten für elektrochemische Anwendungen abgehandelt. Insbesondere geht es um die Anwendung in Wasserstoff-Brennstoffzellen. Als Ergebnis einer sorgfältigen Literatur¬zusammenfassung der Bereiche Hydrothermolyse, hydrothermale Carbonisierung und Chemie des Hydroxymethylfurfurals wird ein chemisch-mechanistisches Modell zur Entstehung der Hydrothemalkohle vorgestellt. Auf der Basis dieses Modells wird ein neues Additiv zur hydrothermalen Carbonisierung von Zuckern vorgestellt. Die Verwendung des einfachen Additivs, genauer Borax, erlaubt eine wesentlich verkürzte und zu niedrigeren Temperaturen hin verschobene Prozessführung mit höheren Ausbeuten. Anhand des mechanistischen Modells wird ein Einfluss auf die Reaktion von Zuckern mit der reaktiven Kohlenvorstufe (Hydroxymethylfurfural) identifiziert. Die chemische Wirkung des Minerals Borax in der hydrothermalen Carbonisierung wird im Folgenden zur Herstellung vielfältig anwendbarer, hochporöser Kohlen mit einstellbarer Partikelgröße genutzt. Zum Abschluss des ersten Teils ist in einer Serie einfacher Experimente die Anwendbarkeit des mechanischen Modells auf die Verwendung „echter“ Biomasse in Form von Wassermelonenabfall gezeigt. Im zweiten Teil werden verschiedene cyano-haltige ionische Flüssigkeiten zur ionothermalen Synthese von Hochleistungskohlen verwendet. Durch Variation der ionischen Flüssigkeiten und Verwendung unterschiedlicher Synthesebedingungen wird die Herstellung hochaktiver, metallfreier Katalysatoren für die elektrochemische Reduktion von Sauerstoff erreicht. In der direkten Reduktion von Sauerstoff zu Wasser (wie sie in Brennstoffzellen Anwendung findet) werden, verglichen zu konventionellen Platin-basierten elektrochemischen Katalysatoren, erstaunliche Aktivitäten erreicht. In einem anderen Beispiel wird die selektive Herstellung von Wasserstoffperoxid zu sehr geringen Kosten vorgestellt. Abschließend wird anhand der Verwendung der ionischen Flüssigkeit 1-Ethyl-3-methylimidazolium-tetracyanoborat eine detaillierte Betrachtung zur Herstellung von graphitischem Borcarbonitrid vorgestellt. Unter Verwendung unreaktiver Salze, als einfaches Werkzeug zur Einführung großer inneren Oberflächen wird erstmals die elektrokatalytische Aktivität eines solchen Materials in der elektrochemischen Sauerstoffreduktion gezeigt.

Ionic liquids (ILs) are nowadays a large and widely explored class of ionic compounds that melt below 100 °C. Due to their attractive properties, ILs are now of growing interests in a variety of inorganic materials preparation. However, most studies have put much focus on the description of new synthetic strategies. The chemical reactivity of ILs in the reactions is often neglected. In this dissertation, a series of metal chalcogenides were synthesized using the decompositions of ILs. The role or chemical reactivity of ILs in the reactions was demonstrated in detail. The hierarchical desert-rose-like SrTiO3 particles have been successfully prepared based on an ethylene glycol (EG) mediated one-pot IL-assisted solvothermal synthetic route. The used basic ionic liquid tetrabutylammonium hydroxide (TBAH) serves as an alkaline source and can also replace EG as the sole solvent to synthesize polyhedral SrTiO3, showing “all-in-one” solvent and reactant. A series of metal sulfides, such as Sb2S3, Bi2S3, PbS, CuS, Ag2S, ZnS, and CdS have been obtained from a choline chloride/thioacetamide based deep eutectic solvent (DES, an IL analog solvent) by a simple and general synthetic method. The reaction mainly proceeds in two steps: i) the dispersion of metal salts in the DES and the formation of a metal-DES complex, and ii) the decomposition of the metal-DES complex and formation of the final products. In addition, the chemical reactivity of phosphonium based ILs with selenium and tellurium at above 220 °C was systematically investigated by a series of dissolution experiments, tracking the solute selenium and tellurium species by nuclear magnetic resonance (NMR). NMR results clearly indicate some common decomposition mechanisms for quaternary phosphonium ILs at a relatively high temperature in the presence of selenium or tellurium. The decomposition of the quaternary phosphonium cations should proceed by an elimination of one alkyl substituent via an SN2 reaction, forming the respective trialkylphosphane selenides or tellurides in the presence of selenium or tellurium, which is then responsible for the genuine dissolution of selenium or tellurium. However, in the case of tellurium, the dissolution behavior is much more complicated compared to that of selenium. The coupling of P and Te which indicates a P–Te bond formation is only observed in the NMR spectra when a sufficient amount of tellurium (e.g. Te : IL = 1 : 1) is provided. The existence of a parallel-competitive IL decomposition route besides the SN2 reaction is regarded as the side reaction for the dissolution of tellurium. This may at least partially explain the relatively lower solubility of tellurium in phosphonium based ILs compared to that of selenium.

Die vorliegende Arbeit beschäftigt sich mit der Synthese und Charakterisierung mesoporöser monolithischer Silica und deren Hybridmaterialien mit Ionischen Flüssigkeiten (ILs, ionic liquids). Zur Synthese der Silicaproben wurde ein Sol-Gel-Verfahren, ausgehend von einer Präkursorverbindung wie Tetramethylorthosilicat angewendet. Der Katalysator mit der geringsten Basizität führte zum Material mit der kleinsten Porengröße und der größten spezifischen Oberfläche. Eine Kombination von porösen Silica mit ILs führt zur Materialklasse der Silica-Ionogele. Diese Hybridmaterialien verbinden die Eigenschaften eines porösen Festkörpers mit denen einer IL (Leitfähigkeit, weites elektrochemisches Fenster, gute thermische Stabilität) und bieten vielfältige Einsatzmöglichkeiten z.B. in der Katalyse- Solar- und Sensortechnik. Um diese Materialien für ihren Verwendungszweck zu optimieren, bedarf es deren umfassenden Charakterisierung. Daher wurde in der vorliegenden Arbeit das thermische Verhalten von Silica-Ionogelen unter Verwendung verschiedener 1-Ethyl-3-methylimidazolium [Emim]-basierter ILs untersucht. Interessanterweise zeigen die untersuchten ILs deutliche Änderungen in ihrem thermischen Verhalten, wenn diese in porösen Materialien eingeschlossen werden (Confinement). Während sich die untersuchten reinen ILs durch klar unterscheidbare Phasenübergänge auszeichnen, konnten für die entsprechenden Hybridmaterialien deutlich schwächer ausgeprägte Übergänge beobachtet werden. Einzelne Phasenübergänge wurden unterdrückt (Glas- und Kristallisationsübergänge), während z.B. Schmelzübergänge in verbreiterten Temperaturbereichen, zum Teil als einzeln getrennte Schmelzpeaks beobachtet wurden. Diese Untersuchungen belegen deutliche Eigenschaftsänderungen der ILs in eingeschränkten Geometrien. Über Festkörper-NMR-Spektroskopie konnte außerdem gezeigt werden, daß die ILs in den mesoporösen Silicamaterialien eine unerwartet hohe Mobilität aufweisen. Die ILs können als quasi-flüssig bezeichnet werden und zeigen die nach bestem Wissen höchste Mobilität, die bisher für vergleichbare Hybridmaterialien beobachtet wurde. Durch Verwendung von funktionalisierten Präkursoren, sowie der Wahl der Reaktionsbedingungen, kann die Oberfläche der Silicamaterialien chemisch funktionalisiert werden und damit die Materialeigenschaften in der gewünschten Weise beeinflußt werden. In der vorliegenden Arbeit wurde der Einfluß der Oberflächenfunktionalität auf das thermische Verhalten hin untersucht. Dazu wurden zwei verschiedene Möglichkeiten der Funktionalisierung angewendet und miteinander verglichen. Bei der in-situ-Funktionalisierung wird die chemische Funktionalität während der Sol-Gel-Synthese über ein entsprechend funktionalisiertes Silan mit in das Silicamaterial einkondensiert. Eine postsynthetische Funktionalisierung erfolgt durch Reaktion der Endgruppen eines Silicamaterials mit geeigneten Reaktionspartnern. Um den Einfluß der physikalischen Eigenschaften der Probe auf die Reaktion zu untersuchen, wurden pulverisierte und monolithische Silicamaterialien miteinander verglichen. Im letzten Teil der Arbeit wurde die Vielfältigkeit, mit der Silicamaterialien postsynthetisch funktionalisiert werden können demonstriert. Durch die Kenntnis von Struktur-Eigenschaftsbeziehungen können die Eigenschaften von Silica-Ionogelen durch die geeignete Kombination von fester und mobiler Phase in der gewünschten Weise verändert werden. Die vorliegende Arbeit soll einen Beitrag zur Untersuchung dieser Beziehungen leisten, um das Potential dieser interessanten Materialien für Anwendungen nutzen zu können. / This work describes the synthesis and characterization of mesoporous monolithic silica and its hybrid materials with ionic liquids (ILs). For synthesis of the silica samples a sol-gel method was used. The catalyst with the weakest basicity leads to the material with the smallest pore size and the largest specific surface area. Combination of porous silica with ILs yields silica-ionogels. These hybrid materials combine the properties of porous solids with the properties of ILs (which is e.g. high conductivity, wide electrochemical stability window, and good thermal stability) and therefore offer a variety of possible applications like catalysis, solar and sensing. To optimize these materials for specific applications there is a need to understand their structure-composition-property relations. For this reason the thermal behavior of silica-ionogels was studied using different 1-ethyl-3-methylimidazolium [Emim]-based ILs. Interestingly the ILs show a clear change in their thermal behavior upon confinement in porous silica. Whereas the pure ILs show distinct phase transitions, the hybrid materials exhibit considerably weaker phase transitions. Phase transitions are suppressed (glass- and crystallization phase transitions); melting transitions show multiple melting peaks. Furthermore solid-state NMR also shows that ILs in mesoporous silica exhibit unusual high mobility. The confined ILs can therefore be classified as quasi-liquid and represents to our best knowledge the highest mobility observed so far in ionogels. By using functionalized silane precursors and different reaction conditions the silica surface was chemically functionalized which further changes the material properties. In a final approach a post-synthetic functionalization was performed by reaction of the selected groups of a silica material with suitable reactants. To study the effect of the physical appearance on the characteristics of the final material, powdered and monolithic samples were studied. In the last part of the work the versatility of post-synthetic silica functionalization was demonstrated. The current work contributes to a better understanding of structure-property correlations, to improve the potential of these interesting materials for possible applications.

No description available.

Ionic liquids (ILs) are nowadays a large and widely explored class of ionic compounds that melt below 100 °C. Due to their attractive properties, ILs are now of growing interests in a variety of inorganic materials preparation. However, most studies have put much focus on the description of new synthetic strategies. The chemical reactivity of ILs in the reactions is often neglected. In this dissertation, a series of metal chalcogenides were synthesized using the decompositions of ILs. The role or chemical reactivity of ILs in the reactions was demonstrated in detail. The hierarchical desert-rose-like SrTiO3 particles have been successfully prepared based on an ethylene glycol (EG) mediated one-pot IL-assisted solvothermal synthetic route. The used basic ionic liquid tetrabutylammonium hydroxide (TBAH) serves as an alkaline source and can also replace EG as the sole solvent to synthesize polyhedral SrTiO3, showing “all-in-one” solvent and reactant. A series of metal sulfides, such as Sb2S3, Bi2S3, PbS, CuS, Ag2S, ZnS, and CdS have been obtained from a choline chloride/thioacetamide based deep eutectic solvent (DES, an IL analog solvent) by a simple and general synthetic method. The reaction mainly proceeds in two steps: i) the dispersion of metal salts in the DES and the formation of a metal-DES complex, and ii) the decomposition of the metal-DES complex and formation of the final products. In addition, the chemical reactivity of phosphonium based ILs with selenium and tellurium at above 220 °C was systematically investigated by a series of dissolution experiments, tracking the solute selenium and tellurium species by nuclear magnetic resonance (NMR). NMR results clearly indicate some common decomposition mechanisms for quaternary phosphonium ILs at a relatively high temperature in the presence of selenium or tellurium. The decomposition of the quaternary phosphonium cations should proceed by an elimination of one alkyl substituent via an SN2 reaction, forming the respective trialkylphosphane selenides or tellurides in the presence of selenium or tellurium, which is then responsible for the genuine dissolution of selenium or tellurium. However, in the case of tellurium, the dissolution behavior is much more complicated compared to that of selenium. The coupling of P and Te which indicates a P–Te bond formation is only observed in the NMR spectra when a sufficient amount of tellurium (e.g. Te : IL = 1 : 1) is provided. The existence of a parallel-competitive IL decomposition route besides the SN2 reaction is regarded as the side reaction for the dissolution of tellurium. This may at least partially explain the relatively lower solubility of tellurium in phosphonium based ILs compared to that of selenium.

As the UN summit in September 2015 addressed with the Sustainable Development Goals (SDG), our planet faces great challenges.[1] Not only since then has the role of synthetic materials chemistry been discussed in this context.[2–16] This not only concerns the development of new materials with outstanding properties such as catalysts, materials for energy conversion, and cost-efficient energy converting and storage materials, but also a reduction of the energy consumption of established functional material syntheses. Therefore, new approaches addressing the three main categories to promote the potential for energy and resource efficiency have been proposed: lowering the temperature of the synthetic processes, improving the yield and purity of the materials, and reducing the amount of waste materials. In this context a number of low-temperature processes have been established, in which mainly solvents, i.e. amines and alcohols, are used in combination with previously synthesised precursors as the solubility of the starting materials limits their usability and most elements are not soluble in these solvents. Novel solvents like ionic liquids (ILs) showcase growing interest as they are considered particularly resource-efficient.[17,18] ILs are defined as liquids that are comprised entirely of ions, with melting points below 100 °C. Continuing on from the reported work in this field, this thesis focuses on investigating the ability of ILs in the syntheses for known chalcogenides at lower temperatures and the synthesis of new materials. The main focus lies on conversions with high atom economy, especially by starting from the elements and completely recycling the IL afterwards, and mechanistic studies elucidating the intermediate dissolved species. Furthermore, as imidazolium based ILs, and their derived LEWIS-acidic ILs [BMIm]Cl/nAlCl3 mixtures, have proven to be good crystallisation media in inorganic syntheses, and the class of mostly room-temperature liquid ILs (RTILs) based on phosphonium cations [P66614]Cl showcased the ability to dissolve red phosphorous, Pred, and the heavier chalcogens S, Se, and Te, this work mainly focuses on these two IL systems. This was also chosen as an in-depth understanding of the activation and resource-efficient synthesis of these chalcogenides has still not been established. As they are RTILs, they also made the characterisation of the reactive and dissolved species by liquid state NMR, Raman, UV/Vis spectroscopy and electrochemical characterisation possible. This expands the knowledge of which main group elements and ore-like starting materials can be used in ionothermal synthesis. As a starting point the thermoelectrically interesting materials class of tellurides is addressed. The under normal conditions hard to dissolve element tellurium readily dissolves in phosphonium ILs with the cations [P66614]+ and [P4444]+. In ILs with carboxylate anions a deep purple hue of the IL already occurred by dissolving tellurium at temperatures of 60 °C. Investigations on the solutions in the acetate ILs revealed the formation of tellurium anions (Ten)2– with chain lengths up to at least n = 5, which are in a dynamic equilibrium with each other. Since external influences could be excluded and no evidence of an IL reaction was found, disproportionation of the tellurium is the only possible dissolution mechanism. However, the spectroscopic detection of tellurium cations in these solutions is difficult, but the coexistence of tellurium cations, such as (Te4)2+ and (Te6)4+, and tellurium anions could be proven by cyclic voltammetry and electrodeposition experiments. DFT calculations indicate that electrostatic interactions with the ions of the ILs are sufficient in stabilizing both types of tellurium ions in solution.[19] In contrast, the acetate ILs show insufficient conversion in reactions of coin metals (Cu, Ag, Au) with tellurium to the corresponding tellurides, especially at low temperatures, however the chloride ILs successfully synthesise Cu2–xTe, CuTe, AuTe2 and Ag2Te. As the synthesis of the tellurides in neat ILs at temperatures down to 60 °C was only sufficient for the system Ag-Te, with a full conversion of the elements to Ag2Te, this was chosen as a model system for further investigations. Even at room temperature, a quantitative yield was achieved by using either 2 mol% of [P66614]Cl in dichloromethane or a planetary ball mill. The unexpected finding that phosphane-free [P66614]Cl also allows the quantitative synthesis of Ag2Te at 60°C implies an additional activation mechanism independent from the phosphane, which is yet unknown.[20] Subsequently, the manifoldly-used lighter chalcogen sulphur is tested for the synthesis of sulphides. Direct synthesis of binary sulphides of B, Bi, Ge, Mo, Cu, Au, Sn, In, Ti, V, Fe, Co, Ga, Ni, Al, Zn, and Sb in [P66614]Cl was tested at 100 °C, i.e. below the melting point of sulphur. Under these conditions, substantial sulphide formation occurred only for nickel (Ni3S4, Ni3S2, NiS) and copper (Cu2S, CuS). Sb showed no formation of crystalline sulphide, but after addition of EtOH, an orange material precipitated which was identified as amorphous metastibnite.[21] As generating these elements from their ores is highly energy consuming, direct dissolution experiments of the crystalline stibnite in [P66614][OAc] and Cl– were investigated and resulted in yellow solutions, from which the amorphous form can be precipitated upon exposure to EtOH air without any sign of decomposition of the IL. In particular, follow-up investigations were conducted on the solubility of Sb2S3 for follow-up chemistry in the LEWIS-acidic IL [BMIm]Cl · 4.7 AlCl3 at 160 °C which resulted in the formation of the novel chloride-terminated [Sb13S16Cl2]5+ quadruple-heterocubane cation-containing compound [Sb13S16Cl2][AlCl4]5.[21] Addition of CuCl in a slightly modified reaction resulted in the formation of the layered semiconductor Cu(Sb2S3)[AlCl4]. From this the AlCl3 can be leached by treatment with 0.1 molar hydrochloric acid, yielding a compound with the presumed composition Cu(Sb2S3)Cl.[22] As ILs showed to be able to activate elements that are insoluble in common solvents, and the formation of Sb2S3 from reactions mixtures of the elements raised the question of whether only the sulphur forms a mobile species or if antimony could additionally activated, the synthesis of binary antimony compounds directly from elements was explored as they are highly discussed as replacements for silicon-based semiconductors. Therefore the 12 elements Ti–Cu, Al, Ga, In, and Te, which are known to form binary compounds with Sb, were reacted with Sb in [P66614]Cl under inert conditions in a simple closed glass flask with vigorous stirring for 16 h at 200 °C. This resulted in the formation of NiSb, InSb, Cu2Sb and Sb2Te3. The applied reaction temperature is several hundred degrees below the temperatures required for solvent-free conversions. Compared to reactions based on diffusions in the solid state, reaction times are much shorter. The IL is not consumed and can be recycled. Since the reaction with Cu showed almost complete conversion, the influences of reaction time, temperature and medium were further investigated. In a diffusion experiment, Cu2Sb formed on the copper, which indicates that antimony forms mobile species in these ILs. These systematic studies hence deliver a contribution to how ILs can help in the synthesis of new materials and how they can make a difference in the synthesis of inorganic materials as well in the context of “GREEN CHEMISTRY”. This can help in developing a more educated choice/toolbox of IL systems for reducing energy costs by reducing the temperature from high temperature inorganic syntheses to syntheses near room-temperature by using the elements as starting materials, with a high atom economy for the synthesis of known and new materials.

Für den Einsatz in Autobatterien gibt es besondere Anforderungen an den Elektrolyten im Bereich der Energie- und Leistungsdichten, um beispielsweise thermische Verluste gering zu halten. Hochleitfähige Elektrolyte mit Leitfähigkeiten im Millisiemensbereich sind hier ebenso notwendig wie auch sichere, d.h. möglichst nicht brennbare und einen niedrigen Dampfdruck besitzende Materialien. Um diese Vorgaben zu erreichen, ist es notwendig, einen polymeren Separator zu entwickeln, welcher auf brennbare organische Lösungsmittel verzichtet und damit eine drastische Steigerung der Sicherheit gewährleistet. Gleichzeitig müssen hierbei die Leistungsvorgaben bezüglich der Leitfähigkeit erfüllt werden. Zu diesem Zweck wurde ein Konzept basierend auf der Kombination von einer polymeren sauerstoffreichen Matrix und einer ionischen Flüssigkeit entwickelt und verifiziert. Dabei wurden folgende Erkenntnisse gewonnen: 1. Es wurden neuartige diacrylierte sauerstoffreiche Matrixkomponenten mit vielen Carbonylfunktionen, für eine gute Lithiumleitfähigkeit, synthetisiert. 2. Es wurden mehrere neue ionische Flüssigkeiten sowohl auf Imidazolbasis als auch auf Ammoniumbasis synthetisiert und charakterisiert. 3. Die Einflüsse der Kationenstruktur und der Einfluss der Gegenionen im Bezug auf Schmelzpunkte und Leitfähigkeiten wurden untersucht. 4. Aus den entwickelten Materialien wurden Blendsysteme hergestellt und mittels Impedanzspektrometrie untersucht: Leitfähigkeiten von 10-4S/cm bei Raumtemperatur sind realisierbar. 5. Die Blendsysteme wurden auf ihre thermische Stabilität hin untersucht: Stabilitäten bis 250°C sind erreichbar. Dabei wird keine kristalline Struktur beobachtet. / Within the field of energy storage and charge transfer, the lithium polymer batteries are one of the leading technologies, due to their low manufacture cost and their possible variety of packaging shapes. Despite their good thermal stability and very good weight to energy ratio, lithium ion batteries use as a electrolyte system a mixture of ethylene carbonate and diethyl carbonate as solvent which have a high risk of deflagration when they come in contact with water. Thus the developement of new materials for lithium-ion-batteries are necessary. For the electrolyte there are special requirements in terms of energy- and power density e.g. in order to minimize thermal loss. High conductivity electrolytes with conductivities in the range of milisiemens are as essential as safe materials, like non flammable non-volatile materials. To fulfill these requirements it is important to develop a polymeric lithium ion conductor, which is free of flammable organic solvents in order to ensure safety. Simultaneously it is also ,mandatory to achieve high performances in terms of ion-conductivity. Therefore a concept based on a combination of an oxygen rich polymeric matrix and ionic liquids was developed and verified. Following results were achieved . 1. Synthesis of new diacryalted oxygen rich matrix components with many carbonylfunctions for a good lithium ion transport. 2. Synthesis and characterization of new ionic liquids based on imidazol or ammonium compounds. 3. Investigation of the influences of the cation structure and counter ions for melting points and ion conductivity. 4. Creation of Blendsystems with the developed materials 5. Thermal investigations of these solid-state-electrolytes with DSC and TGA measurements, resulting in thermal stabilities up to 250°C.No crystallization were observed. 6. investigation of these solid-state-electrolytes via AC-impedance spectrometry, resulting in conductivities of 10-4S/cm at room temperature.

A NMR study of the structure-dynamics relationships in heterogeneous materials is presented. In the first part, transport in soft-matter systems is studied using the pulsed field gradient NMR technique (PFG NMR). The molecular crowding effect in biological matter has been addressed using polymer solutions as model systems. By performing ensemble-based diffusion studies, the earlier obtained data on anomalous diffusion have been complemented. The transition to normal diffusion on a larger time scale has been shown. Taking advantages of the NMR approach, transport properties of microemulsions consisting of micellar colloids dissolved in liquid crystals have been investigated. The self-diffusivities measured under equilibrium conditions have shown weak correlations with microscopic ordering and macroscopic phase transitions occurring in the systems under study. The formation of micelles is shown to be decisive for macroscopic separation at the isotropic-nematic transition. The second part of the thesis covers heterogeneous effects in diffusion for fluids in porous solids, as probed using a combination of NMR diffusometry and structure characterization methods. Ionic liquids have been investigated, revealing a complex behavior under confinement. The attempts to correlate the observed characteristics of the ionic liquids with their internal chemical structure were undertaken. Finally, the series of nanoporous glasses with tunable pore structure characteristics were studied. Strong correlations between their structure and the preparation conditions as well as between the resulting transport properties have been shown.

Main group polycations and transition metal clusters had traditionally been synthesized via high-temperature routes by performing reactions in melts or by CTR, at room-temperature or lower temperature by using so-called superacid solvents, and at room-temperature in benzene–GaX3 media. Considering the major problems associated with higher temperature routes (e.g. long annealing time, risk of product decomposition, and low yield) and taking into account the toxicity of benzene and liquid SO2 in room-temperature or lower temperature synthesis, a soft and sustainable chemical approach has been developed, employing a Lewis-acidic IL [bmim]Cl/AlCl3. This new alternative reaction medium has proven to be an excellent solvent system for the single–step synthesis of main group polycations and transition metal clusters. X-ray diffraction and Raman spectroscopy have been used for the structural characterization of the isolated compounds. Physical properties and quantum chemical calculations of some of the compounds have also been carried out.

Chemical synthesis of materials is facing enormous challenges at the present time. The necessary transition toward more sustainable economic processes requires new materials as well as optimized production of well-established materials. However, inorganic materials (e.g., ceramics or alloys) are typically produced industrially by high-temperature processes at up to 2000 °C. A relatively new approach for inorganic synthesis is based on so-called ionic liquids. Ionic liquids (ILs) — often defined as salts with melting points below 100 °C[1] — are usually composed of sterically demanding organic cations and (often) polyatomic anions, which can be selected in order to tune the properties of the IL. Owing to the distinctive physicochemical properties of ILs (e.g., wide liquidus range, high redox and thermal stability, (usually) negligible vapor pressure, tunable polarity), they have gained interest for a wide range of applications. Among the numerous inorganic materials accessible in ILs have been remarkable examples, especially in main-group element chemistry. For instance, a new metastable modification of germanium in the clathrate-II structure[2] or the largest known naked, main-group element cluster [Sn36Ge24Se132]24– (“Zeoball”).[3] The introduction of Lewis-acidic ILs has enhanced the convenience of polycation syntheses and enabled substitution of carcinogenic or toxic substances like benzene, SO2, or AsF5.[4] A considerable number of polycations of group 15 or 16 elements has been synthesized in ILs. The utilization of an IL as reaction medium can be decisive for the composition, structure, and physical properties of the (polycationic) reaction product.[5] In order to broaden the knowledge on synthesis techniques for inorganic materials near ambient temperature based on ILs, this thesis aimed at two goals: • Explorative synthesis of new inorganic compounds in ILs • Elucidating the influence of ILs on product formation For these two goals, metal-rich (polycationic) compounds of group 15 were chosen as promising chemical system, owing to the effectiveness of alkylimidazolium-based Lewis-acidic ILs for the synthesis of this class of compounds. A variety of new polycationic compounds has been successfully synthesized in Lewis-acidic ILs based on 1-n-butyl-3-methylimidazolium (or 1-ethy-3-methylimidazolium) halides and halogenido-aluminates. Determination of the crystal structures by single-crystal X-ray diffraction enabled analysis of their bonding situation supported by quantum-chemical calculations. In general, the employed ILs enabled syntheses with a high selectivity for the yielded polycation. Depending on the investigated chemical system, the following parameters were pinpointed to have significant influence: • Choice of starting materials • Choice of cation as well as anion of the IL • Reaction temperature • Concentration of starting materials in the IL The investigations were supported by NMR spectroscopy, which led to the discovery of nanoparticles of red phosphorus. This finding may stimulate the development of an easily accessible, reactive form of phosphorus without the hazardous drawbacks of the white allotrope. In addition, in situ NMR measurements in ILs were proven a viable option for mechanistic investigations. Conventional solid-state reaction as well as ionothermal syntheses yielded the new layered compounds M2Bi2S3(AlCl4)2 (M = Cu, Ag), which can be interpreted as Bi2S3 molecules embedded in MAlCl4 salts. The choice of starting materials was found to have a crucial influence on the crystallized polytype. Omitting the IL hindered the formation of crystals suitable for single-crystal structure determination. The three new main-group element heteropolycations [Bi6Te4Br2]4+, [Bi3S4AlCl]3+, and [Sb13Se16]7+ as well as known [Bi4Te4]4+ has been synthesized under ionothermal conditions. The Lewis-acidic ILs proved to be exceptional solvents for elements and their halides, and likewise for Bi2S3 and Bi2Te3. Hence, these solvents are not only advantageous reaction media for pnictogen and chalcogen chemistry but also potential (selective but expensive) ore-processing agents. These excellent solvent capabilities extend to complex ternary compounds including heavy transition metals such as Bi16PdCl22 and elemental platinum. This gave rise to the synthesis of metal-rich salts containing [Bi10]4+ antiprisms with an endohedral palladium or, for the first time, platinum atom. Furthermore, the filled bismuth polycation [Rh@Bi9]4+ or the complex cluster [Rh2Bi12]4+ could be obtained from dissolution and conversion of Bi12−xRhX13–x (X = Cl, Br) depending on the employed IL. Real-space bonding analysis revealed that [Rh2Bi12]4+ acquires a unique standing between dative bonding by bismuth polyions and mixed clusters following Wade-Mingos rules. References [1] J. S. Wilkes, P. Wasserscheid, T. Welton, in Ionic Liquids in Synthesis (Eds.: P. Wasserscheid, T. Welton), Wiley-VCH Verlag GmbH & Co. KGaA, 2007, pp. 1–6. [2] A. M. Guloy, R. Ramlau, Z. Tang, W. Schnelle, M. Baitinger, Y. Grin, Nature 2006, 443, 320–323. [3] Y. Lin, W. Massa, S. Dehnen, J. Am. Chem. 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