Synthesis, spectral characterization, SC-XRD, Hirshfeld, DFT and in silico antidiabetic activity of novel imine (E)-N-(2-nitro benzylidene) naphthalene-1-amine, a newly synthesized imine: A theoretical and experimental evaluation

Abstract

A novel imine compound, (E)-N-(2-nitrobenzylidene) naphthalene-1-amine (NBNA), has been successfully synthesized through the reaction of o-nitrobenzaldehyde and 1-naphthylamine. The structural characterization of NBNA has been carried out using single-crystal X-ray diffraction (SC-XRD) analysis. The XRD analysis reveals that NBNA crystallizes in a monoclinic crystal system with the space group P21/c. The unit cell parameters of NBNA are determined as follows: a = 7.549 (4) Å, b = 19.680 (11) Å, c = 9.598 (6) Å, β = 107.96(3)°, and Z = 4. Notably, the crystal structure of NBNA is stabilized by π-π stacking interactions between the naphthyl moiety and the nitrophenyl moiety, occurring at a perpendicular distance of 3.542 Å. Quantum mechanical calculations employing the B3LYP/6–311G(d,p) method in GAUSSIAN 09 software have been employed to determine the optimized geometry, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), Time-dependent Density Functional Theory (TD-DFT), and chemical reactivity descriptors of NBNA. The vibrational spectroscopic data has been compared with the DFT/B3LYP/6–311G(d,p) method and scaled using MOLVIB for analysis. By examining the NBOs, the distribution of electron density and the interaction between orbitals can be analysed, shedding light on the stability and reactivity of the compound. Additionally, frontier molecular orbital analysis and molecular electrostatic potential mapping are discussed to gain further insights. First-order hyperpolarizability studies have been conducted to explore the nonlinear optical behaviour of the molecule. By calculating and comparing the first-order hyperpolarizability of the compound with a reference molecule (in this case, urea), the obtained results indicate that the crystal of the molecule possesses a significantly higher first-order hyperpolarizability value (19.124 times urea) suggesting its potential as a promising material for nonlinear optical applications. An in-depth examination of the Hirshfeld surface and two-dimensional fingerprint plot has been conducted to gain insights into the intermolecular interactions of the compound. Molecular docking studies are performed on the PPARγ target to assess the molecule's potential antidiabetic activity, revealing a binding energy of -6.71 kJ/mol for NBNA with the target. The comprehensive assessment of the compound's ADMET properties provides valuable insights into its pharmacological potential and aids in the selection of promising drug candidates.