Synthesis, Crystal Structure, Hirshfeld Surface Analysis and DFT Calculations of 2-[(2,3-dimethylphenyl)amino]-N’-[(E)-thiophen-2-ylmethylidene]benzohydrazide

Abstract

Hydrazones are an important class of organic compounds, which exhibit large pharmacological applications. Hydrazones have long been used for the synthesis of a wide range of useful heterocyclic compounds due to their reactivity toward electrophiles and nucleophiles. Herein, a hydrazone derivative, 2-[(2,3-dimethylphenyl)amino]-N’-[(E)-thiophen-2-ylmethylidene]benzohydrazide, noted C<inf>20</inf>H<inf>19</inf>N<inf>3</inf>OS was synthesized and its three-dimensional structure was determined by X-ray crystallography. Structural characterization by X-ray crystallography was supported by Density Functional Theory (DFT) calculations. Intermolecular interactions in the crystal network were determined using Hirshfeld surface analyses. The optimized geometry, global reactivity descriptors, Natural Bond Orbital (NBO) analysis, and HOMO-LUMO orbitals of the molecule were computed using the DFT-B3LYP method and 6–311++G (d,p) basis set. C<inf>20</inf>H<inf>19</inf>N<inf>3</inf>OS has a monoclinic system and P2<inf>1</inf>/c space group with parameters a = 13.9774 (13) Å, b = 16.3851 (16) Å, c = 8.2101 (8) Å, β = 105.429 (7)° and Z = 4. C<inf>20</inf>H<inf>19</inf>N<inf>3</inf>OS forms an S (6) ring motif with an intramolecular N–H⋯O hydrogen bond. In the crystal, the molecule chains along the c-axis direction are linked by C–H⋯O hydrogen bond. Atomic charges were predicted using the Mulliken population and the NBO theory. The molecular electrostatic potential (MEP) picture was drawn using the same level of theory to visualize the chemical reactivity and charge distribution on the molecule. The local reactivity was examined by determining the Fukui functions and dual descriptor indices. © 2019 Elsevier B.V.