Chirality of the molecular assembly determined by intra-/inter-N–H⋯O hydrogen bonding in doubly substituted N-octanoylglyoxylic amides

N-Octanoylglyoxylic amides have been synthesized from N-octanoylisatins and their self-assembly analyzed in the solid state by X-ray crystallography. Of the seven compounds, only two utilize intramolecular N1–H1⋯O2 hydrogen bonds, whereas five of them forgo this intramolecular hydrogen bond to achieve two centrosymmetric N–H⋯O bonds possessing a non-planar conformation with intramolecular triple Cdouble bond; length as m-dashO⋯Cdouble bond; length as m-dashO dipolar contacts. These alternative conformations with resulting intermolecular interactions influence the self-assembly process distinctly; the former have molecules packed in chiral space groups whereas the latter associate in non-chiral space groups.