Structural analysis and charge transfer properties of a novel pyrazoline derivative: potential energy scan, XRD, DFT and molecular docking studies

Abstract

The title molecule, 1-[3-(6-bezyloxy-2-hydroxy-4-methyl-cyclohexa-2, 4-dienyl)-5-phenyl-4, 5-dihydro-pyrazol-1-yl]-propan-1-one was synthesized and characterized by FTIR, 1H NMR, 13C NMR and single-crystal X-ray diffraction technique. The optimized geometry is calculated using density functional theory (DFT). A good linear correlation was observed between experimental data and theoretical structural parameters (DFT). Predicted vibrational frequencies were assigned and compared with the experimental IR spectra and they support each other. To determine conformational flexibility and hence to predict the stable geometry, potential energy scan of the molecule was obtained with respect to selected degree of freedom about O18–C19 torsional angle varied from − 180° to + 180° in steps 20°. NBO analysis was carried out for the molecule to check possible hydrogen bond interactions to correlate with those of X-ray data. Molecular stability is mainly due to weak but collective contributions of significant nonconventional C–H…π, π–π and C–H…O-type hydrogen bond interactions and those interactions also quantified by Hirshfeld surface analysis. The thermal stability of the compound was determined with the aid of thermo-gravimetric analysis and differential thermal analysis. The molecular docking study was carried out against the title molecule with 5DBM protein receptor active sites.