Crystallographic Analysis under Pressure Can Resolve Ambiguity Regarding Chirality: The Case of an Imidazolium-Based Coordination Network

Hydrostatic pressure can be a valuable aid in the structural study of a chiral compound, avoiding disorder and providing an unambiguous description of the stereochemistry of the chemical system. This follows from the single-crystal X-ray diffraction studies performed on the chiral framework [Y₄(ox)₅(L*)₂(H₂O)₄]·2.5H₂O, <b>1</b> (L* = (<i>S</i>,<i>S</i>)-1,3-bis(carboxyethyl)imidazolium)), for hydrostatic pressures up to 3.6 GPa. The positional disorder for the chiral groups obtained at ambient pressure vanished when the crystal was subjected to hydrostatic pressure (2.4 GPa), unambiguously confirming the stereoisomer for all the chiral carbon centers and the homochiral nature of <b>1</b>.