Crystal structure, Hirshfeld surface analysis and DFT studies of 2-(2,3-di-hydro-1H-perimidin-2-yl)phenol.

The asymmetric unit of the title compound, C(17)H(14)N(2)O, contains two independent mol-ecules each consisting of perimidine and phenol units. The tricyclic perimidine units contain naphthalene ring systems and non-planar C(4)N(2) rings adopting envelope conformations with the C atoms of the NCN groups hinged by 44.11†(7) and 48.50†(6)° with respect to the best planes of the other five atoms. Intra-molecular O-H⋯N hydrogen bonds may help to consolidate the mol-ecular conformations. The two independent mol-ecules are linked through an N-H⋯O hydrogen bond. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (52.9%) and H⋯C/C⋯H (39.5%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Density functional theory (DFT) optimized structures at the B3LYP/ 6-311†G(d,p) level are compared with the experimentally determined mol-ecular structure in the solid state. The HOMO-LUMO behaviour was elucidated to determine the energy gap.