Pyridylthioether-hydroxycoumarin Schiff base as selective Zn2+ fluorescence sensor, application in life cell imaging and uses of resulting complex as secondary probe for ATP sensing

[Display omitted] •Pyridylthioether appended coumarin Schiff base (HL) is a tetradentate N2OS donor ligand.•Upon addition Zn2+ ion to HL enhances emission in presence of other ions.•The complex formation is established by Job’s plot, Mass spectral and crystal structure.•HL has been used for imaging and sensing Zn2+ ions in Vero Cells.•DFT computation of ligand and complex is used for spectral interpretation. Pyridylthioether appended coumarin Schiff base (7-hydroxy-4-methyl-8-((2-(pyridin-2-ylmethylthio)phenylimino)methyl)-2H-chromen-2-one (HL)) exhibits fluorescence augmentation with Zn2+ and the limit of detection (LOD) is 0.078μM. Formation of complex, [ZnL(CH3COO)], has been ascertained by X-ray crystallography, and also by Job’s plot and Mass spectra. The fluorogenic complex, [ZnL(CH3COO)] identifies ATP in presence of organic and inorganic phosphates and also other anions. The DFT and TD DFT computation have been carried out with ligand and complex to interpret the spectral properties. The practical applicability of HL has been examined in the identification of Zn2+ in intracellular fluid in RAW 264.7 cells (Mus musculus, mouse).