Struktur-Eigenschaftsbeziehungen Mullit-ähnlicher Verbindungen mit einsamen Elektronenpaaren

点击翻译按钮获取中文摘要

In this project, similarities and differences in crystal structure and structure controlled property values of mullite-type compounds carrying a lone-electron pair (LEP) should be worked out. The structural characterization will be carried out by diffraction methods, the structural short range order and effects using spectroscopic methods. These compounds provide a good model system to investigate phases with and without LEPs. The stereochemical distortion of the cation coordination should influence a number of physicochemical properties like the thermal or mechanical behavior of the phases. It should be proven how far properties could be modified while changing the structural modification of mullite-type compounds as well as the possibility to create new phases with different forms of connectivity. Structurally important questions are the deformation and distortion of the octahedral chains as well as the interconnecting building units with respect to the stereochemical activity of the LEPs. An important scientific development is expected comparing the experimental results with the analysis results of quantum chemical modeling. These DFT calculations are used to describe the influence of the LEP on one hand and enable a detail interpretation of infrared on Raman spectra on the other hand.