Aryl–perfluoroaryl stacking interactions, hydrogen bonding and steric effects in controlling the structure of supramolecular assemblies of N,N′-diaryloxalamides

Cocrystallization of N,N′-diaryloxalamides with pentafluorophenol (pfp) leads to 1 : 2 molecular complexes, which were characterized by X-ray crystallography. The non-planar oxalamide molecules and pfp assemble into polymeric tapes with use of the N–H⋯O and O–H⋯O hydrogen bonds and phenyl–perfluorophenyl interactions, whereas the molecules adopting planar conformations form with pfp flat trimers held together by intermolecular hydrogen bonds creating two 7-membered rings.