ESIPT-based dual-emissive perimidine derivative as a rapid and sensitive sensor for Cu²⁺ and Al³⁺: Construction of...

An ESIPT based fluorescent perimidine derivative oPSDAN was developed and characterized by ¹H NMR, ¹³C NMR and mass spectroscopy. The study of the photo-physical properties of the sensor unveiled its selectivity and sensitivity towards Cu²⁺ and Al³⁺ ions. The sensing of ions was accompanied by colorimetric change (for Cu²⁺) as well as emission turn-off response. The binding stoichiometries of sensor oPSDAN with Cu²⁺ ion and Al³⁺ ions were determined to be 2:1 and 1:1, respectively. The binding constants and detection limits for Cu²⁺ and Al³⁺ were calculated from the UV-vis and fluorescence titration profiles as, 7.1 × 10⁴ M^-1, 1.9 × 10⁴ M^-1 and 9.89 nM, 1.5 × 10^-8 M, respectively. The mechanism was established by ¹H NMR as well as mass titrations and was supported by DFT and TD-DFT calculations. The UV-vis and fluorescence spectral results were further utilized for construction of memory device, encoder and decoder. Sensor-oPSDAN was also tested for determining Cu²⁺ ions in drinking water.