High resolution X-ray single crystal diffraction

Identifier:  TDX:2811

Handle: https://hdl.handle.net/20.500.11797/TDX2811

Authors:  Escudero Adán, Eduardo Carmelo

Abstract:
radiación de molibdeno para asignar la configuración absoluta de una serie de moléculas orgánicas. Las moléculas medidas fueron seleccionadas teniendo en cuenta que el elemento más pesado de su composición química fuera el oxígeno. Es bien conocido que la dispersión anómala de este tipo de compuestos es muy débil y dificulta la asignación de configuración absoluta mediante esta técnica. El resultados de este trabajo demuestran que la metodología empleada es muy efectivo para poder asignar inequívocamente la configuración absoluta correcta en este tipo de moléculas. This thesis uses high resolution single crystal X-ray diffraction data in order to obtain experimental detailed charge density distribution maps that can exhibit intra and intermolecular interactions. The charge density maps are obtained through the multipolar refinement. Particularly, this work focuses in lasts classified non-covalent attractive interactions due to sigma and pi holes, triel, tetrel, pnictogen and chalcogen bonds. The weakness of these interactions make necessary very accurate and precise maps. In the same manner, in this works they have been determined the quadrupolar moment and the molecular electrostatic potential of a series of phenyl rings substituted with different chemical groups. The experimental data obtained in this way have been used to validate theoretical predictions. Eventually in this work, high resolution single crystal X-ray diffraction data using molybdenum radiation has been employed to assign the absolute configuration of a series of organic molecules. The measured molecules were selected containing oxygen as heaviest atom since the anomalous dispersion of these kind of compounds is very weak. The use of high resolution data has been proved to be effective in order to unequivocally assign the correct absolute configuration in this kind of molecules.