Crystal Structure, DFT, Hirshfeld Surface Analysis, and Energy Frameworks Study of 8-hydroxy1,2,3,5,6,7-hexahydropyrido [3,2,1-ij]quinoline-9- Carbaldehyde

In the title compound, C13H15NO2, the fused non-aromatic rings of the julolidine moiety incorporate envelope conformations. In order to create a S(6) ring motif, the hydroxy group establishes an intramolecular hydrogen connection with the aldehyde O atom. Weak intermolecular C—H O hydrogen bonds help to stabilize the crystal structure. The molecular structure of a solid-state compound is obtained experimentally and compared to optimal density functional theory (DFT) structures at the B3LYP/6-311 G(d,p) level. The different intermolecular interactions and the crystal packing strength of the compound have been determined by Hirshfeld surface analysis. To study the stability of the molecule and recognize the dominant energy type, energy frameworks were constructed, using various intermolecular interaction energies.