Stabilization of Supramolecular Assembly of N-Substituted Benzylidene Acetohydrazide Analogs by Non-Covalent Interactions: A Concise Experimental and Theoretical Approach

Herein, the crystallineN-substituted benzylidene acetohydrazide derivatives:N '-(4-bromo-2-fluorobenzylidene)-2-((6-chloropyridin-2-yl)oxy) acetohydrazide (BFBAH) and 2-((6-chloropyridin-2-yl)oxy)-N '-(4-methoxybenzylidene) acetohydrazide (MOBAH) were produced and the structures were characterized and confirmed by the NMR spectroscopy and single crystal analysis. SC-XRD study disclosed that the molecules are connected with each other in the form of dimers through hydrogen bonding in the crystalline network ofBFBAHandMOBAH. Additionally, the theoretical calculations were performed using the DFT/B3LYP/6-311G(d,p) functional. The hyperconjugation and intermolecular hydrogen bonding were explored by using NBO analysis. Hirshfeld surface analysis analyzing intra and intermolecular interactions, uncovered that supramolecular assemblies have been stabilized by N-H...O and C-H...O intermolecular hydrogen bonds, as well as van der Waals interactions. The quantum theory of atoms in molecules (QT-AIM) study corroborates that both significant N-H...O and C-H...O H-bonds are strong in nature. Besides, global reactivity indices were computedviathe energies of HOMO and LUMO orbitals.