Bis(2-pyridylmethyl)alkyl(thioalkyl)diamines as promising scaffolds for the construction of fluorescent and redox chemosensors for transition and post-transition metal ions

► Tetradentate aminopyridines are proposed as receptor units in fluorescent and redox chemosensors. ► The response of the chemosensors to heavy metals in solution is discussed. ► The role of the receptor units is studied from a comparative analysis of the results.