New fluoro- and chromogenic chemosensors for the dual-channel detection of Hg2+ and F−

Two novel thioxanthone-based compounds 1a and 1b which possess thiosemicarbazone as binding site were developed for the dual-channel detection of Hg2+ and F−. Upon treatment with Hg2+ and F− separately, the probes’ fluorescence is effectively quenched, meanwhile 1a and 1b show evident naked-eye color variations after addition of F−: colorless to yellow. They both exhibit specific sensitivity and selectivity for Hg2+ or F− over other examined ions in tetrahydrofuran (THF) solution.