Highly Selective and Sensitive Dual Channel Schiff Base Chemosesnsors for the Detection of Al(III), Fe(III) & Cu(II)

Abstract

Two Schiff bases derived from 2,4-dihydroxy acetophenone were synthesised and characterized by IR, UV-Vis, 1 H NMR, Mass spectral studies and single crystal Xray diffraction studies. They were grown into a single crystal in 1:1 ethanol acetonitrile medium by slow evaporation technique and belong to monoclinic crystal system with P21/c space group. Hirshfeld surface analysis based on DFT method with 3-21G as basis set was used to calculate various intermolecular interactions. Finger print plots were made to find out the percentage of different types of interactions. The cation recognizing profile of the Schiff base receptors were explored by UV-Vis and fluorescence methods. The receptor 1 NMEPDHAPI was found to recognize Al 3+ and the receptor 2 NMPDHAPIwas found to recognize Fe 3+ and Cu 2+ ions selectively over a panel of other metal ions such as Na + , Mg 2+ ,Ca 2+ ,Mn 2+ , Co 2+ , Ni 2+ , Zn 2+ , Sr 2+ ,Cd 2+ ,Ba 2+ ,Hg 2+ and Pb 2+ . The stoichiometry ratio of the receptors with Al 3+ and Fe 3+ &Cu 2+ obtained by the Job’s plot was 2:1. The binding constant of the receptor 1 for Al 3+ was 10.11 X 10 3 and that ofreceptor 2 for Fe 3+ and Cu 2+ were 1.43 X 10 +2 and 1.65 X 10 +2 respectively. The detection limits for Al 3+ , Fe 3+ and Cu 2+ were 6.5318 X 10 -9 M, 1.265 X 10 -6 M and 4.086 X 10 -6 M respectively.