In the crystal, the 1-decyl chains are in a ‘fully extended’ conformation and inter­calate in the crystal packing to form hydro­phobic bands. The packing is further organized by π–π-stacking and C=O⋯π-ring inter­actions. The inter­molecular inter­actions were investigating by Hirshfeld surface analysis.

In the title molecule, C17H23NO2, the dihydroindole portion is planar (r.m.s. deviation = 0.0157 Å) and the nonyl substituent is in an `extended' conformation. In the crystal, the nonyl chains intercalate and the dihydroindoledione units are associated through C—H...O hydrogen bonds to form micellar blocks. Based on the Hirshfeld surface analysis, the most important intermolecular interaction is the H...H interaction.

In the title compound, C17H17N3O, the indolone ring system is almost planar, with an angle of 0.76 (14)° between the five- and six-membered rings. The dicyanomethylidene substituent lies close to the indolene plane. In the crystal, offset π-stacking interactions between five- and six-membered rings of indolene stack the molecules along thec-axis direction.

In the title molecule, C18H16N2O2, the seven-membered diazepinone ring adopts a boat conformation. An intramolecular N—H...O hydrogen bond encloses anS(6) ring. The two propynyl substituents each point away from the same face of the benzodiazepinone ring system. In the crystal, C—H...O hydrogen bonds form double chains of molecules along thec-axis direction.

In the title compound, C14H14N2O2, the dihydroquinoxaline moiety deviates slightly from planarity. In the crystal, zigzag chains are formed by inversion-related C—H...O hydrogen bonds. Adjacent chains are associated through pairwise C—H...π(ring) and π-stacking interactions.