Triphenylamine based new Schiff base ligand: Solvent dependent selective fluorescence sensing of Mg2 + and Fe3 + ions

•Triphenylamine based multiple metal ion sensing Schiff base chemosensor•Highly selective fluorescence sensing of Mg2 + up to the level of 10− 6 M•Solvent dependent fluorescence sensing•Selective fluorescence sensing of Fe3 + as well as Mg2 + in tetrahydrofuran•Distinguishable naked eye detectable color for Mg2 + and Fe3 +

A new Schiff base ligand based on triphenylamine (1) was synthesized and demonstrated solvent dependent selective fluorescence sensing of Mg2 + and Fe3 + ions up to ppm level (10− 6 M). Highly selective turn-on fluorescence for Mg2 + was observed in DMSO as well as DMF (λmax = 506 nm, Φ = 0.007 (1), 0.17 (1 + Mg2 +)). Interestingly, in THF, 1 showed strong turn-on fluorescence for Fe3 + (blue, λmax = 460 nm, Φ = 0.064) as well as for Mg2 + (greenish yellow). Interference studies confirm that Ca2 + that strongly competes with Mg2 + sensing had negligible interference. The practical application of 1 for selective fluorescence sensing of Mg2 + from different water samples has also been demonstrated.

Graphical abstractTriphenylamine based 1,2-phenylene diamine Schiff base ligand exhibited solvent dependent fluorescence sensing of Mg2 + and Fe3 + ions.Figure optionsDownload full-size imageDownload as PowerPoint slide