Crystals of Prochiral Bromo-Oxoamide by Surface Diffraction: Chirality Determination by Anomalous Scattering

Crystallisation of chiral molecules under applied magnetic field have attracted large attention during the last years. The axial-chiral molecule bromo-oxoamide will be crystallized at surfaces, the molecule can adapt enantiopure crystals of either R- or S- type. The grown crystals will be investigated by anomalous X-ray diffraction, the experiments will be performed at the K-edge of bromine. Grazing Incidence X-ray Diffraction will be used, since the crystals are provided at substrate surfaces. Due to the presence of a surface, the well-established method based on Friedel pairs cannot be applied. Instead, a specific selection of Bragg peak intensities will be compared which have different impact on anomalous scattering. For verification of the reliability of the method, crystals with known chirality of enantiopure molecules bromo-ß-lactam will be studied too. This work will show, if anomalous X-ray diffraction is a possible tool to determine the chirality of crystals prepared at surfaces using grazing incidence X-ray diffraction.