The design of compounds with novel and improved physico-chemical properties as advanced functional materials with a specific application spectrum requires the knowledge about possible supramolecular packing motifs and their experimental control in crystalline lattice. Besides the structure of the individual molecule, non-covalent interactions play a significant role in the determination of molecular conformation, along with the formation of three-dimensional supramolecular architecture in a crystal as a requirement for molecular recognition processes, and the related bioactivity. Involvement of functional groups will contribute to the formation of a predefined packing motif due to their well-defined interactions. The strength and directionality of these interactions create characteristic packing motifs, which can be used for the design of supramolecular arrangements by the development of appropriate strategies for the precise control of their topology. Most relevant of these non-covalent interactions are stacking interactions and hydrogen bonds, which have been subjects of extensive study in the last two decades. In recent literature, substantial efforts have been put in by various researchers towards the understanding of interactions involving organic fluorine and the role they play in generating different packing motifs which guides assembling of molecules in the crystal lattice.

A series of mono- and difluorinated benzanilides have been synthesized and characterized to unravel the importance of interactions involving organic fluorine. The effect of fluorine substitution on the molecular conformation and the solid-state organization of the molecules in the crystalline lattice have been discussed in terms of changes in molecular conformation and the supramolecular aggregation. It is noteworthy that the meta- and para-isomers (mono and difluorinated) are isostructural, with the ortho-isomers possessing minor conformational variations. Furthermore, the molecular conformation as obtained by theoretical DFT calculations is different from the solid-state conformation highlighting the importance of co-operative features brought by N–H⋯O and C–H⋯O hydrogen bonds, along with weak intermolecular interactions involving organic fluorine and aromatic C–H⋯π contacts in the solid state.