Speaker
Description
Chirality has become increasingly significant across a range of disciplines, including chemistry, materials science, biology, and the pharmaceutical industry. Resonant (anomalous) X-ray scattering provides a direct method for probing chirality in crystals. By tuning the incident energy near atomic absorption edges, resonant scattering breaks the symmetry between lattice planes (−h −k −l) and (h k l), known as Friedel’s law, by introducing a measurable intensity difference between Friedel pairs. This principle has been well established in single crystal X-ray diffraction (SCXRD) for assigning absolute configuration using the Flack parameter. However, in many experimental geometries, such as grazing incidence X-ray diffraction (GIXD), access to complete Friedel pairs is restricted. This talk presents a new approach for assigning the absolute configuration of enantiomorphic chiral crystals of the Br-oxo molecule. Simulations of the energy-dependent structure factors for different reflections show distinct energy dependences for the two absolute configurations, whereas others remain identical. By comparing the measured and simulated energy dependent intensities, the absolute configuration can be assigned using the intensity of a single reflection, even in cases where conventional approaches rely on multiple Friedel pairs. This approach opens new opportunities for studying chiral crystals and offers potential extensions to thin-film systems.