Effect of electronegativity on structural, spectrophotometric and thermo-chemical properties of fluorine and chlorine substituted isoxazoles by DFT method

The effect of electronegativity (F and Cl atom) on structural, spectrophotometric, thermo-chemical properties, and solvent effect on electronic absorption spectra of {3-(3,5-dichloro-2-hydroxyphenyl)-5-[(4-fluorophenyl)amino] isoxazol-4-yl}(phenyl)methanone (Ia) and {3-(3,5-dichloro-2-hydroxyphenyl)-5-[(4-chlorophenyl)amino] isoxazol-4-yl}(phenyl) methanone (Ib) were studied by DFT method using PBE1PBE functional with 6-311++ g (d, p) basis set. The results show that the electronegativity of halogen group affect the bond length, atomic charges, excited wavelength, molecular orbital energy gap, vibration frequency, thermo-chemical parameters, and stability of compounds.