DAB-Am-4 based colorimetric receptors for fluoride and pyrophosphate anions

Flexible four armed polypropylenimine tetraamine dendrimer (DAB-Am-4) core linked through urea moieties to a chromophore (aza group) gave rise to the colorimetric sensor 1 for fluoride ions, and a fluorophore (naphthyl group) attached to a similar assembly resulted in 2 which showed an excellent association constant with pyrophosphate anions.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Two new easy-to-prepare four armed dendrimer (DAB-Am-4) based neutral receptors are reported. ► Sensor 1 effectively recognizes biologically important F− and HP2O73− anion. ► To the best of our knowledge, the receptor 1 is the first naked-eye-detectable chemosensor containing four-armed dendritic core that permits discrimination between different anionic substrates as a result of disparate change in color. ► From the binding study experiments, receptor 2 can be termed as selective sensor for F− and HP2O73− anions.