Hirshfeld Surface analysis, spectroscopic, biological studies and molecular docking of (4E)-4-((naphthalen-2-yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one

Abstract

Abstract In the present work, the newly synthesized compound (4E)-4-((naphthalen-2-yl)methyleneamino)-1,2-dihydro-2,3-dimethyl-1-phenylpyrazol-5-one was studied by both structural and spectral (FT-IR, 1H and 13C NMR chemical shifts and electronic-UV-Vis.), using experimental and theoretical methods. All theoretical computations of the title compound were performed by using the density functional theory (DFT/B3LYP) quantum mechanical method with 6–311++G(d,p) basis set and Gaussian 09W program. The vibrational assignments were controlled and performed with VEDA 4 program based on potential energy distributions (PED). The experimental FT-IR spectrum was studied in solid phase in the range of 4000 and 400 cm−1. Also, the experimental and theoretical 1H and 13C NMR chemical shifts in chloroform and UV–Vis. spectral analysis in methanol were examined theoretically and experimentally. To support UV–Vis. data (both experimental and theoretical), the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) computations were carried out over with methanol optimized structure. Furthermore, Hirshfeld and MEP (Molecular Electrostatic Potential) surface analyses were performed to observe better intermolecular interactions in the crystal packing. Antimicrobial studies showed that the compound has inhibition zones with different sizes with various microorganisms, indicating the different interactions of the examined compound with the growth, cell wall structure and permeability of cell membrane of the tested organisms. Furthermore, molecular docking studies were conducted for the Schiff base compound and appropriate reference drugs against 5fsa and 1kzn proteins, highlighting the different mode of interactions assumed by the Schiff base compound compared to that of the reference drugs which rationalize the difference in biological effects.