Synthesis and characterization of bis[N′-(4-carboxybenzylidene)]-pyridine-2,6-dicarbohydrazide: Colorimetric and fluorometric modulation in presence of F− ions

F− ion recognition with a novel organic compound bis[N′-(4-carboxybenzylidene)]-pyridine-2,6-dicarbohydrazide (L) is monitored using UV-vis, fluorescence and 1H NMR spectroscopic titrations and DFT/TD-DFT calculations which supported the experimental results.