Molecular structure of 4-benzoyl-3-ethylcarboxylate 1-(4-methoxyphenyl)-5-phenyl-1H-pyrazole: A combined experimental and theoretical study

The title molecule, 4-benzoyl-3-ethylcarboxylate 1-(4-methoxyphenyl)-5-phenyl-1H-pyrazole, (C26H22N2O4), was synthesized and characterized by IR–NMR spectroscopy and single-crystal X-ray diffraction. In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the title compound in the ground state have been calculated using the spin-restricted Hartree–Fock (HF) and density functional theory (DFT/B3LYP) method with the 6-31G (d, p) basis set, and compared with the experimental data. To determine conformational flexibility, molecular energy profile of the tittle compound was obtained by semi-empirical (AM1) with respect to selected degree of torsional freedom, which was varied from −180° to +180° in steps 10°. Besides, molecular electrostatic potential (MEP) distribution, frontier molecular orbitals (FMOs) and thermodynamic properties of the title molecule were investigated by theoretical calculations at the B3LYP/6-31G (d, p) level.