Co-crystallization studies of the syn - and anti -atropisomers of triphenyl-based perfluorinated halogen bond donors with halides

After recent two-point recognition studies using polyfluorinated twofold-iodinated 1,3- and 1,4-substituted triphenyl-based halogen bond (XB) donors, further crystallographic studies towards their binding behaviour were performed. To this end, syn - and anti -isomers of the XB donors were crystallized as pure compounds, as complexes with the halides chloride, bromide and iodide, and were investigated using X-ray diffraction. All complexes obtained showed strong halogen bonds with varying geometry and stoichiometry. The acquired data was then also compared to that of previously investigated fourfold-iodinated XB donors. This comparison showed strong differences again in geometry and stoichiometry, as well as slight differences in XB strength.