Solvatochromic behavior of a pyrene-pyrimidine-based Schiff base and detection of heavy metal ions in aqueous media

The synthesis and solvatochromic behavior of pyrimidine based Schiff-base (PYPH) were studied to develop a fluorescent chemo sensor for the detection of Hg2+ in aqueous solution. The characterization of PYPH was investigated on the basis of UV–vis, FTIR, 1H-NMR and mass spectral data. PYPH displays selective fluorescent turn-off response to Hg2+ in aqueous solution. The sensitivity and selectivity of PYPH toward Hg2+ among different metal ions was examined by absorption, fluorescence, 1H-NMR and mass spectral studies. Binding stoichiometry (2:1) has been confirmed by a Job’s plot, HRMS spectral studies and 1H-NMR analysis. A low detection limit was 4.2 × 10−6 M for Hg2+. Ground state geometry of PYPH has been optimized using density functional theory (DFT). These results demonstrate that PYPH has promise to detect Hg2+ ion in environmental analysis systems.