Ethyl and methyl esters of commercial rhodamines B, 19, 101 and 110 and propyl and butyl esters of commercial rhodamine B were synthesized and isolated with different counterions (yields 70–98%). The 1H and 13C NMR spectral data for these compounds were fully assigned by a combination of one‐ and two‐dimensional experiments. The Fourier transform IR and UV–visible spectra were also recorded and the
A novel fluorescein-rhodamine dyad probe has been synthesized and its chemosensory applications are explored. Anion and cation specific responses of the probe permit ratiometric detection of Hg2+ and fluoride ions, individually and collectively, with different fluorescence outputs. The presence of other commonly coexistent ions does not affect the Hg2+ and fluoride ion detection ability of the probe. The probe is highly sensitive to Hg2+ and fluoride ions and it can detect Hg2+ and fluoride ions even at ppb level concentrations. The probe is non-toxic under the experimental conditions, cell permeable and useful for the imaging of intracellular Hg2+ and fluoride ions. (C) 2014 Elsevier Ltd. All rights reserved.