Versatile Schiff-base hydrazone fluorescent receptors: Synthesis, spectroscopy and complexation studies

A family of emissive acyclic ligands (1–4) and their Cu2+ and Zn2+ metal complexes has been synthesized and characterised by microanalysis, IR, MALDI mass spectrometry, UV–Vis and fluorescence emission. For comparative purposes, the coordination ability of all chemosensors (1–4) towards the same metal ions was explored in solution (with the help of the UV–Vis and emission spectroscopy) and in gas phase (by MALDI mass spectrometry). The formation of mononuclear complexes with two or three units of ligands was observed during the entire process.