Interplay between Halogen Bonding and Lone Pair-π Interactions: A Computational and Crystal Packing Study
Résumé
The supramolecular organization of modified thiophenes resulting from N⋅⋅⋅I halogen bonding (XB) has been studied. X‐ray diffraction analyses of two polymorphs of the same supramolecular complex showed an arrangement controlled by halogen‐bonded pyridyl and tetrafluoroiodobenzene rings, one case with and the other without the presence of two different lone pair (lp)⋅⋅⋅π interactions, namely O⋅⋅⋅pyridyl and I⋅⋅⋅tetrafluoroiodobenzene contacts. To shed light on the interplay between these interactions, quantum mechanical calculations were performed at the ωB97X‐D/6‐31+G(d,p) level on both systems in the gas phase. The longer N⋅⋅⋅I distance observed in the crystal structure without lp⋅⋅⋅π interactions was also corroborated by dispersion‐corrected DFT. These results represent the first case in which a synergy between lp⋅⋅⋅π interactions and XB is observed experimentally and confirmed by calculations.