Crystal structure and Hirshfeld surface analysis of dimethyl 3,3′-{[(1E,2E)-ethane-1,2-diylidene]bis-(azanylylidene)}bis(4-methylbenzoate)

The title Schiff base compound, C20H20N2O4, synthesized by the condensation reaction of methyl 3-amino-4-methylbenzoat and glyoxal in ethanol, crystallizes in the the monoclinic space group P2(1)/n. The molecule is Z-shaped with the C-N-C-C torsion angle being 47.58 (18)degrees. In the crystal, pairs of molecules are linked via C-H center dot center dot center dot N hydrogen bonds, forming centrosymetric dimers with an R-2(2)(8) ring motif; this connectivity leads to the formation of columns running along the a-axis direction. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to explore the intermolecular interactions and revealed that the most significant contributions to the crystal packing are from H center dot center dot center dot H (49.4%), H center dot center dot center dot O/O center dot center dot center dot H (19.0%) and H center dot center dot center dot C/C center dot center dot center dot H (17.5%) contacts. Energy frameworks were constructed through different intermolecular interaction energies to investigate the stability of the compound. The net interaction energies for the title compound were found to be electrostatic (E-ele = - 48.4 kJ mol(-1)), polarization (E-pol = -9.7 kJ mol(-1)), dispersion (E-dis = - 186.9 kJ mol(-1)) and repulsion (E-rep = 94.9 kJ mol(-1)) with a total interaction energy, E-tot, of -162.4 kJ mol(-1).