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) H-1 and C-13 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 degrees to +180 degrees in steps 10 degrees. 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. (C) 2012 Elsevier B.V. All rights reserved.