Crystalline salt synthesis from p-dimethylaminobenzaldehyde and o-phenylenediamine, single crystal XRD study along with computational investigation

• The salt is synthesized by the condensation of p -dimethylaminobenzaldehyde and o -phenylenediamine under the gaze of CCl 3 COOH. • Solid state assembly is mainly stabilized by interactions between ionic species (N-H ⋯ Cl, C-H ⋯ Cl) and with water (N-H ⋯ O, O-H ⋯ Cl). • H ⋯ H and H ⋯ Cl contacts are important regarding stabilization of the supramolecular assembly . • Dispersion energy played the most prominent energy in stabilization of the supramolecular assembly of the compound. • Computational study results are consistent with the corresponding ones of single crystal XRD. The condensation reaction of p -dimethylaminobenzaldehyde with o -phenylenediamine under the gaze of CCl 3 COOH results in the synthesis of 2-(4-(dimethylamino)phenyl)- 1 H -benzo[d]imidazole-3-ium chloride ( DBIC ) crystalline salt. The X-ray diffraction method confirms that DBIC is crystallized in monoclinic crystal system with space group P 2 1 / n and chemical formula 2(C 15 H 16 N 3 ) +0 ·2(Cl) - ·H 2 O. XRD showed that DBIC is a salt with asymmetric unit composed of two cations, two anions and a water molecule. Difference between the orientation of two cations concerning each other is explored by molecular overlay plot. N-H ⋯ O, N-H ⋯ Cl, O-H ⋯ Cl, C-H ⋯ Cl, C-H ⋯ π, π ⋯ π intermolecular interactions stabilize the solid-state assembly which are explored via Hirshfeld surface analysis. The H ⋯ H and H ⋯ Cl are the most dominating elemental contacts within the crystal structure. DFT study reveals the superb electronic structures and reactivity of DBIC . The presence of noncovalent interactions between Cl-atom and H-atoms of cationic moiety can impart excellent NLO features in our complex. The molecular electrostatic potential and electron localizing function predicts the surface reactivity and bonding electrons in complex. The optical and nonlinear optical properties were anticipated through hyperpolarizability response.