Rhodamine 6G hydrazone bearing thiophene unit: A highly sensitive and selective off–on fluorescent chemosensor for Al3+.

A rhodamine derivative ( R1 ) has been synthesized by a hydrazone formation of rhodamine 6G hydrazide with 3-methylthiophene-2-carbaldehyde, which exhibits high selectivity and sensitivity as an “off–on” fluorescent sensor toward Al 3+ in water containing media. The binding process was confirmed by UV–vis absorption, fluorescence measurements, mass spectroscopy and DFT calculation. The probe functions by Al 3+ induced hydrolytic cleavage of the imine-bond to produce an intense rhodamine-based emission. To test the practical use of the probe, the determination of Al 3+ in real water samples was also evaluated. [ABSTRACT FROM AUTHOR]