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

• Published in: ChemistrySelect (Weinheim) 2020-09, Vol.5 (34), p.10618-10631
• Main Authors: Khalid, Muhammad, Ali, Akbar, Tariq, Jahrukh, Tahir, Muhammad Nawaz, Aliabad, Hossein Asghar Rahnamaye, Hussain, Ishtiaq, Ashfaq, Muhammad, Khan, Muhammad Usman
• Format: Article
• Language: English
• Subjects: DFT; Hirshfeld surface analysis; N-substituted Benzylidene Acetohydrazide; Non-Covalent Interactions; QT-AIM; SC-XRD
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202002653

Herein, the crystalline N‐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 of BFBAH and MOBAH. 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 computed via the energies of HOMO and LUMO orbitals. Two newly synthesized N‐substituted benzylidene acetohydrazides were characterized via SC‐XRD and NMR techniques. Furthermore, theoretical approaches were used for exploring their stabilities owing to non‐covalent interactions in the said supramolecular assemblies. Consequently, SC‐XRD and theoretical findings proved to be in a good agreement.