Abstract

A novel Schiff base of 2-((E)-(2-amino-5-methylphenylimino)methyl)-5-(difluoromethoxy)phenol (R) was synthesized and characterized by FT-IR, 1H&13C-NMR and Mass spectra. The receptor with the interference of different metal ions in the existence of Mg2+ ion turned to yellow to green color. The selectivity and sensitivity Mg2+ ion caused to the maximum fluorescence-emission intensity at 524 nm, with excitation-wavelength at 378 nm. Further experiments confirmed receptor R binding with Mg2+. The job’s plot conforms to 1:1 stoichiometry complex formation. The strong fluorescence is due to the PET effect. The receptor can be recovered by EDTA titration and the emission intensity also returned to value equivalent to unbound ligand. PDB: 4j96 was used for molecular docking for receptor R. The cytotoxicity effect treatment was done with increasing the concentration of HeLa cells to predict IC50 value. The HOMO/LUMO energy gap calculated compared between R results as 3.48eV and R-Mg2+ alpha and the beta value calculated low energy value at 2.27eV.

Key words: Schiff base; Mg2+ ion; colorimetric; Fluorometric; cytotoxicity; DFT.