Synthesis and characterization of new light emitter symmetrical phenoxazinium salt and its potential application as sensor for assessment of Hg2+.

The sensitization of the excited triplet state of a novel symmetrical Bis(dialkylamino)phenoxazinium salt was developed in the presence of Hg(2+). This effect was used to determine the concentration of Hg(2+) in different water samples. The phenoxazinium salt sensor was characterized by different spectroscopic tools such as: UV, FTIR, NMR and fluorescence spectra. The sensor has an emission band at 347 nm in DMSO. Hg(2+) in DMSO at pH 5.6 can remarkably quench the fluorescence intensity of the sensor at 347 nm and a new band was appeared at 436 nm due to the strong complex formation between Hg(2+) and sensor. The quenching of the band intensity at 347 and the enhancement of the intensity of the new band at 436 were used to determine the Hg(2+) in different waste water samples. The dynamic range found for the determination of Hg(2+) concentration is 8.7 × 10(-10) - 1.4 × 10(-6) mol L(-1) with a detection limit of 5.8 × 10(-10) mol L(-1) and quantification detection limit of 1.8 × 10(-9) mol L(-1).