Molecular and electronic structures of two new Schiff base compounds: (E)-2-bromo-6-[(2-bromo-4-methylphenylimino) methyl]-4-chlorophenol and (E)-2-bromo-6-[(4-bromo-3-methylphenylimino) methyl]-4-chlorophenol

Abstract

Two new Schiff base compounds, (E)-2-bromo-6-[(2-bromo-4-methylphenylimino) methyl]-4-chlorophenol, (I) and (E)-2-bromo-6-[(4-bromo-3-methylphenylimino) methyl]-4-chlorophenol (II) have been synthesized and characterized by X-ray single crystal diffraction, FT-IR, UV-Vis and NMR spectroscopic techniques for this study. Moreover, the density functional theory calculations have been performed at the B3LYP method with 6-311G(d,p) basis set. The gas phase geometry optimizations of two possible forms resulting from the prototropic tautomerism of the title compounds have been obtained. While the X-ray and UV-Vis studies show that the compounds adopt OH tautomeric form in the solid state and solvent media, the density functional theory calculations also confirm that the OH tautomeric form is the most stable for both compounds. The crystal structures exhibit both inter- and intra-molecular hydrogen bond interactions, π-π stacking interactions and halogen bonds which play significant role in building the three dimensional network.