The molecule in the title compound, C15H12N4O2, has a twistedL-shape with the dihedral angle between the aromatic rings of the N-bound benzene and C-bound benzyl groups being 70.60 (9)°. The nitro group is co-planar with the benzene ring to which it is connected [C—C—N—O torsion angle = 0.4 (3)°]. The three-dimensional packing is stabilized by a combination of methylene-C—H...O(nitro), methylene-C—H...π(phenyl), phenyl-C—H...π(triazolyl) and nitro-O...π(nitrobenzene) interactions, along with weak π(triazolyl)–π(nitrobenzene) contacts [inter-centroid distance = 3.8386 (10) Å]. The importance of the specified intermolecular contacts has been verified by an analysis of the calculated Hirshfeld surface.

The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C—C bond; the Cm—Ca—Ca—Cme torsion angle is 38.26 (15)° [m = methylcarboxylate, a = acetyloxy and me = methylene]. While the N-bound ethylcarboxylate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supramolecular double-layers are formed by weak methyl- and methylene-C—H...O(carbonyl) interactions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional interactions between them. The Hirshfeld surface is dominated by H...H (55.7%) and H...C/C...H (37.0%) contacts; H...H contacts are noted in the inter-double-layer region. The interaction energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.

The title compound, C23H24N2O9, is a tetra-substituted pyrrolidine derivative with a twisted conformation, with the twist evident in the C—C bond bearing the adjacent acetyloxy substituents. These are flanked on one side by a C-bound 4-methoxyphenyl group and on the other by a methylene group. The almost sp 2-N atom [sum of angles = 357°] bears a 4-nitrobenzyloxycarbonyl substituent. In the crystal, ring-methylene-C—H...O(acetyloxy-carbonyl) and methylene-C—H...O(carbonyl) interactions lead to supramolecular layers lying parallel to (\overline{1}01); the layers stack without directional interactions between them. The analysis of the calculated Hirshfeld surfaces indicates the combined importance of H...H (42.3%), H...O/O...H (37.3%) and H...C/C...H (14.9%) surface contacts. Further, the interaction energies, largely dominated by the dispersive term, point to the stabilizing influence of H...H and O...O contacts in the inter-layer region.

The title pyrrolidine compound, C18H23NO7, is a tetra-substituted species in which the five-membered ring has a twisted conformation with the twist occurring in the C—C bond bearing the adjacent acetyloxy substituents; the Cm—Ca—Ca—Cp torsion angle is −40.76 (18)° [m = methylene, a = acetyloxy and p = phenyl]. The N atom, which is sp 2-hybridized [sum of bond angles = 359.4°], bears an ethylcarboxylate substitutent and is connected to a methylene-C atom on one side and a carbon atom bearing a 4-methoxyphenyl group on the other side. Minor disorder is noted in the ethylcarboxylate substituent as well as in one of the acetyloxy groups; the major components of the disorder have site occupancies of 0.729 (9) and 0.62 (3), respectively. The most notable feature of the molecular packing is the formation of helical, supramolecular chains aligned along the b-axis direction whereby the carbonyl-O atom not involved in a disordered residue accepts C—H...O interactions from methylene-H and two-C atom separated methine-H atoms to form a six-membered {...HCCCH...O} synthon. Should the name indicate that it is racemic?