Absolute configuration determination of pharmaceutical crystalline powders by MicroED <i>via</i> chiral salt formation

Microcrystal electron diffraction (MicroED) has established its complementary role alongside X-ray diffraction in crystal structure elucidation. Unfortunately, kinematical refinement of MicroED data lacks the differentiation power to assign the absolute structure solely based on the measured intensities. Here we report a method for absolute configuration determination <i>via</i> MicroED by employing salt formation with chiral counterions.