The Structure Determination of Organic Molecules by Co-crystallization of Anthracene-Based Crystallization Chaperone

Single crystal X-ray diffraction is considered to be a highly reliable method for determining the molecular structures and absolute conformation at the atomic level, but this technique is limited to the application of oily organic molecules that are difficult to crystallize. Here, we report an anthracene-based crystallization chaperone TMAPA to overcome the above limitation, where 56 various oily organic guest molecules were co-crystallized with TMAPA in the organic solvent. As a result, 51 high-resolution co-crystal structures of organic guest molecules (chiral or achiral) with TMAPA were determined in a short time so that 51 refined structures of oily organic guest molecules can be readily determined. Importantly, anthracene moieties introduced in the TMAPA structure could not only extend the length of arms to increase the size of pores but also adaptively adopt different conformations leading to an efficient capture of the guest molecule during the co-crystallization process. It is expected that this work will open up new possibilities for structural identification and absolute conformation determination of unknown oily organic molecules.