Crystal structure, Hirshfeld surface analysis and inter-action energy and DFT studies of 2-(2,3-di-hydro-1H-perimidin-2-yl)-6-meth-oxy-phenol.

The title compound, C(18)H(16)N(2)O(2), consists of perimidine and meth-oxy-phenol units, where the tricyclic perimidine unit contains a naphthalene ring system and a non-planar C(4)N(2) ring adopting an envelope conformation with the NCN group hinged by 47.44†(7)° with respect to the best plane of the other five atoms. In the crystal, O-H(Phnl)⋯N(Prmdn) and N-H(Prmdn)⋯O(Phnl) (Phnl = phenol and Prmdn = perimidine) hydrogen bonds link the mol-ecules into infinite chains along the b-axis direction. Weak C-H⋯π inter-actions may further stabilize the crystal structure. The Hirshfeld surface analysis of the crystal structure indicates that the most important contributions for the crystal packing are from H⋯H (49.0%), H⋯C/C⋯H (35.8%) and H⋯O/O⋯H (12.0%) inter-actions. Hydrogen bonding and van der Waals inter-actions are the dominant inter-actions in the crystal packing. Computational chemistry indicates that in the crystal, the O-H(Phnl)⋯N(Prmdn) and N-H(Prmdn)⋯O(Phnl) hydrogen-bond energies are 58.4 and 38.0†kJ†mol(-1), respectively. 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.