This thesis deals with the use of high-resolution single crystal X-ray diffraction data in order to obtain detailed charge density distribution maps. The charge density maps are obtained through the multipolar refinement of the diffracted data. These maps are useful in the study of intra and intermolecular interactions in the solid state. Particularly, the work focuses on experimentally evidencing the so-called triel, tetrel, pnictogen and chalcogen bonds. These are noncovalent interactions involving group 14, 15 and 16 atoms, respectively. They are established between σ-hole or π-hole regions centered at these atoms in a molecule acting as electrophilic sites and nucleophilic regions of another molecule (lone pair or π-system) or negatively charged atom. The weak nature of these interactions requires the use of very accurate and precise electron density maps for their study. Analogously, we have applied the experimentally determined electron density maps to quantify the quadrupolar moment and the molecular electrostatic potential surfaces of a series of substituted phenyl rings containing different functional groups. The obtained experimental data have been used to validate theoretical predictions.
Finally, high-resolution single crystal X-ray diffraction data using molybdenum radiation were employed to assign the absolute configuration of a series of organic molecules. The diffracted molecules contained oxygen atoms as the heaviest elements since the anomalous dispersion of these kind of compounds is very weak. The use of high-resolution data proved to be very effective in the unequivocal assignment of the correct absolute configuration for this kind of molecules.
11-12-2024 
