Determination of spectroscopic properties of p-hydroxybyzaldehyte derivative azo-imin compounds of ester derivatives

In this study, in the first step azo dyes containing an imine group were synthesized by coupling p-Hydroxybenzylidene aniline with the diazonium salts of p-Toluidine, 4-aminophenol, aniline, p-Chloroaniline, p-Fluoroaniline and p-Nitroaniline. In the third step six new azo-azomethine dyes containing acryloyl group, (E)-4-[[[4-[4'-methylphenylazo)phenyl]imino]methyl]phenyl-2-propenoat, (E)-4-[[[4-[4'-hydroxy-phenylazo)phenyl]imino]methyl]phenyl-2-propenoat, (E)-4-[[[4-(phenylazo)phenyl]-imino] methyl] -phenyl-2-propenoat, (E)-4-[[[4-[4'-chlorophenylazo) phenyl] imino]-methyl] phenyl-2-propenoat, (E)-4-[[[4-[4'-nitrophenylazo)phenyl]imino]-methyl] phenyl-2-propenoat were synthesized. The compounds were characterized by melting point, elemental, UV-Vis and IR analyses as well as 1H-NMR and 13C-NMR spectroscopies. Moreover, the experimental data were supplemented with density functional theory (DFT) calculations. The experimental data on FT-IR and UV–Vis spectra of the compounds were compared with theoretical results. The DFT calculations were performed to obtain the ground state geometries of the compounds using the B3LYP hybrid functional level with 6-311++g(2d,2p) basis set. Frontier molecular orbital energies, band gap energies and some chemical reactivity parameters, such as chemical hardness and electronegativity, were calculated and compared with experimental values. A significant correlation was observed between the dipole moment and polarities of the solvents and the absorption wavelength of the compounds. The acryloyl derivatives of the azo-azomethine dyes were prepared with metallic sodium and acryloyl chloride in 1:1 Molar ratio.