Two Schiff Base Compounds Derived from 5-Aminoisophthalic Acid: Chemsensors Properties for Sensing of Metal Ions and Nitroaromatic Compounds

In this work, two Schiff base ligands Z2a and Z2b derived from 5-aminoisophthalic acid were synthesized and their structures were characterized by FTIR, 1H(13C) NMR and mass spectrometries. The compounds were investigated for their chemosensor properties towards metal ions [Na+, K+, Al3+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Pb2+] were examined using colorimetric and spectrophotometric methods (UV-Vis absorption and florescence spectroscopy). Both compounds showed similar sensing properties towards metal ions and they have shown selective sensory properties for Fe+3 and Hg+2 ions. Moreover, the compounds were examined for their fluorimetric sensing abilities for nitroaromatic compounds [4-nitrofenol (NP), nitrobenzene (NB), 2,4-dinitrofenol (DNP), 1,3,5-trinitrophenol (TNP)]. Both compounds showed higher sensitivities for DNP and TNP than NP and NB. Compound Z2b showed the highest sensitivity for DNP with Ksv value of 2.4×104 M-1. Limit of detections for nitroaromatic compounds were calculated and both compounds showed LOD values in micromolar levels. Compound Z2b has shown the lowest LOD value for DNP with 2.77 M.