Synthesis, Characterization and Density Functional Theory Studies of 3-Chlorochromones

Abstract

3-Chlorochromones like 3-chloro-2-(4-methoxyphenyl)-4H-chromen-4-one, 3,6-dichloro-2-(4-chlorophenyl)-4Hchromen-4-one, 6-bromo-3-chloro-2-(4-chlorophenyl)-4H-chromen-4-one, 3,6-dichloro-2-(4-methoxyphenyl)-4Hchromen-4-one and 6-bromo-3-chloro-2-(4-methoxyphenyl)-4H-chromen-4-one have been synthesized and characterized by spectroscopic methods. The density functional theory (DFT) calculations of these molecules were at B3LYP/6-311++G(d,p) level. Optimized geometries, 1H NMR and harmonic fundamental vibrational frequencies were evaluated. The vibrational frequencies and 1H NMR determined experimentally were compared with those obtained theoretically. Thermodynamic properties like entropy, heat capacity, zero point energy, dipole moment, bond length, bond angels, atomic charges and HOMO-LUMO have also been recorded. In addition to this electronic spectra of these molecules are calculated by using TD-DFT method and compared with experimental spectrum. Keyword: 3-chlorochromones, FT-IR, NMR, UV, HOMO- LUMO, DFT/B3LYP.