Molecular docking, vibrational, structural, electronic and optical studies of {4 – (2, 6) dichlorophenyl amino 2 – methylidene 4 – oxobutanoic acid and 4- (2, 5)} dichlorophenyl amino 2 – methylidene 4 – oxobutanoic acid – A comparative study

Abstract

Spectroscopic and structural investigations of 4 – [(2, 6 – dichlorophenyl) amino] 2 –methylidene 4 – oxobutanoic acid (6DAMB) and 4-[(2, 5– dichlorophenyl) amino] 2 – methylidene 4 – oxobutanoic acid (5DAMB) are presented by using experimental (FT-IR and FT-Raman) spectra and theoretical (DFT approach) calculations. Seventy-two characteristic vibrational bands of the title compounds were assigned and compared with available experimental data. Stability of the molecule arising from hyper-conjugative interactions and charge delocalization was analyzed using natural bond orbital (NBO) analysis. Several descriptors determined from the energies of frontier molecular orbital (HOMO and LUMO) were applied to describe the reactivity of the title compound. The dipole moment and first hyperpolarizabilities of the studied compounds indicate that the compound is a good candidate of nonlinear optical materials. Theoretical Ultraviolet–Visible spectra of title compounds have been analyzed using the TD-DFT method. The noncovalent interactions like hydrogen bonding and Van der Waals interaction were identified from the molecular geometry and electron localization function. These interactions in molecules have been studied by using reduced density gradient (RDG) and graphed by Multiwfn. Auto-dock studies reveal that butanoic acid derivatives play a vital role in bonding and results draw us to the concluded that both compounds inhibit Placenta growth factor (PIGF-1) and that have good biological activities. This study may also provide further investigation on butanoic acid derivatives for pharmacological importance.