Conformational and Vibrational Analysis of Chalcone (E)-3-(Furan-2-yl)-1-Phenylprop-2-en-1-one by Density Functional Theory and ab initio Hartree-Fock

Authors : Güventürk Uğurlu

Pages : 148-164

Doi:10.48138/cjo.1025061

View : 28 | Download : 9

Publication Date : 2021-12-31

Article Type : Research

Abstract :The potential energy curves (PEC) of 2 Chalcone (E)-3-(Furan-2-yl)-1-Phenylprop-2-en-1-one (1) were calculated as a function dihedral angle φ(C8-C9-C10-O1) at both ab initio Hartree–Fock (HF) and Density Functional Theory (DFT) using the B3LYP functional together with 6-311++G (d,p) basis set and the syn- and anti-conformers corresponding low energy conformers were determined. The optimized molecular structures, vibrational wavenumbers of the syn- and anti-conformers of title molecule were obtained with the two methods mentioned above. The 1H- NMR and 13C-NMR chemical shift values and frontier molecular orbitals (FMOs) were computed from the optimized structure of both conformers by DFT/B3LYP and HF methods with 6-311++G(d,p) basis set. Also, UV-Vis spectrum of both conformers ware calculated in gas phase via TD-DFT/ B3LYP/6-311++G (d,p) calculation. The equilibrium state (ground state) dipole moment values of the anti and syn conformer were calculated as 3.33 and 3.01 Debye by B3LYP/6-311++ G(d,p) and 4.05 and 3.88 Debye by ab initio HF/6-311++ G(d,p) method. The calculated geometric parameters (bond lengths and bond-dihedral angles) of the molecule were compared with the experimental values in the literature and they were found to be in good agreement. The output chk.file generated from calculation file was used to visualize the electrostatic potential map, and HOMO-LUMO orbitals using GaussView5.0.9 program.
Keywords : Vibrational spectra, DFT, frontier molecular orbitals, Potential energy curve, Dipole moment