Systematic Construction of Ternary Cocrystals by Orthogonal and Robust Hydrogen and Halogen Bonds

A carefully
designed strategy is presented for the construction
of ternary cocrystals, based on the orthogonality of two supramolecular
interaction modes: hydrogen bonding between crown ethers and thioureas
and the halogen bonding between thioureas and perfluorohalocarbons.
Tested on a set comprising two crown ethers, two thioureas and five
halogen bond donors, the strategy resulted in a high, 75% success
rate, with 15/20 component combinations yielding at least one cocrystal.
Crystal structure analysis revealed the interplay between the hydrogen
and halogen bonding motifs, also shedding light on the variables affecting
their formation.