Porphyrin-Disäuren als funktionelle Kationen für Hauptgruppenhalogenidometallat-Verbindungen sowie die Exfoliation von BiI3

Im Rahmen dieses Promotionsprojektes hab ich zwei verschiedene Themengebieten bearbeitet. Themengebiet A beschäftigte sich mit der Exfoliation von Bismuttriodid und in Themengebiet B wird die Verwendung von Porphyrin-Disäuren als funktionale Kationen für Hauptgruppenhalogenidometallat-Verbindungen...

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Bibliographic Details
Main Author: Wagner, Bettina
Contributors: Heine, Johanna (Dr.) (Thesis advisor)
Format: Doctoral Thesis
Published: Philipps-Universität Marburg 2021
Online Access:PDF Full Text
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This doctoral project has two different subjects. Topic A dealt with the exfoliation of bismuth triodide and topic B investigates the use of porphyrinic diacids as functional cations for main group halide metallate compounds. The first topic deals with the exfoliation of bismuth triodide and the further investigation of its surface. I was able to prepare large BiI3 single crystals that are easy to handle, I was able to exfoliated them mechanically and then analyzed their stability to various aging and storage processes. It was found that although bismuth triodide exhibits high stability in the bulk crystal, the surface is rapidly destroyed by ambient air. Subsequently, a variety of different experimental conditions were tested resulting in the identification of water as the trigger of surface decomposition and BiOI as its main product. In addition, during long-term storage under dynamic vacuum, bismuth(I)iodide needles can be observed on the surface. I was able to successfully reproduce the liquid phase exfoliation of bismuth triodide in chlorobenzene and extend it by DLS measurements. In addition, I was able to perform a size separation by cascade centrifugation. I was concerned with the representation of a model system for the bismuth triodide surface. Here I was able to prepare (15-crown-5)BiI3·0.5TIE. In this compound, interactions between the bismuth triodide and the tetraiodoethylene molecules can be observed. In the context of this publication, it was also possible to prepare and fully characterize (15-crown-5)BiI3. It is shown that (15-crown-5)BiI3 can act as halogen bridge acceptor for typical halogen bridge donors such as tetraiodoethylene, so that the production/isolation of (15-crown-5)BiI3·0.5TIE was possible. During the synthesis experiments, other crown ether compounds also appeared that have not been published but have been addressed in this work. These include the compound 8, where the crown ether (12-K-4) ring was opened. Compounds 9 and 10 are compounds where a [Bi3I12]3−-anion occurs and alkali metal crown ether sandwich cations ([(crown ether)2Na]+) were found. The topic around the use of porphyrin diacids as functional cations for main group main group halogenidometalate compounds built on the results of my master's thesis. . was able to prepare, fully characterize, and publish [H2T(Ph)P][BiX5] (X = Br, Cl/Br). This compound exhibits a previously unobserved anion motif in the structural chemistry of halogenidobismutates. It can be seen, also when looking at the unit cell, that the [BiBr5]2−-anion is completely isolated between the cations and no chain formation with further [BiBr5]2−-anions occurs. This is the first square pyramidal isolated halogenidobismutate. The square pyramidal arrangement occurs due to the sterically demanding [H2T(Ph)P]2+- cations. In Figure 6.5 is shown an excerpt of the crystal structure of compound [H2T(Ph)P][BiBr5], illustrating the isolation of the [BiBr5]2−-anion from additional [BiBr5]2−-anions. In addition to this compound, it was also possible to prepare another seven compounds with different porphyrin diacids as cations . These are compounds with halidobismutate, halidoantimonate or halide anions. The porphyrin diacids are fully protonated or methylated in all compounds. This ensures that the porphyrin takes the saddle conformation. The compounds were obtained via both reactions in solution and under solvothermal conditions. The in situ methylation was possible by the addition of methanol as solvent and reactant, in the case of the solvothermal reaction procedure. The compounds all exhibit interactions between cation and the protonated pyrrole nitrogen atoms of the porphyrin backbone. I have been able to access a variety of main group halogenido metalate compounds with porphyrinic diacids as counterions. In the case of compound 6, it has so far only been possible to propose a single crystal structure model, but this already shows an anion structure motif which has not yet been described in the literature. In some of the other compounds, novel anion structure motifs also appear. This shows that porphyrinic diacids are well suited to make new structural motifs of the main group 15 halogenido metalate anions accessible.