Anthracene scaffold as highly selective chemosensor for Al3+ and its AIEE activity

Fluorescent chemosensor, 3-(Anthracen-2-yliminomethyl)-benzene-1,2-diol (ANB) has been synthesized by one-step condensation of 2-aminoanthracene and 2,3-dihydroxybenzaldehyde and characterized using H-1-NMR, FT-IR and Mass spectroscopic techniques. The probe ANB was found to be an efficient 'turn-on' fluorescence chemosensor for the selective detection of Al3+ ion over other metal ions in an aqueous solution. The chemosensor exhibits similar to 27-fold enhancement of emission intensity in presence of Al3+ ion. Fluorescence quantum values for ANB and (Al3+-ANB)-complex are 0.004 and 0.097, respectively. In addition, the binding constant and the limit of detection were found to be 1.22 x 10(4) M-1 and 0.391 mu M, respectively. The chemosensor ANB binds to Al3+ ions in 2:1 stoichiometric ratio which was supported by Job's plot, H-1-NMR titration and florescence titration. Fluorescence reversibility of the sensor complex was well established by adding EDTA in the same condition and a molecular INHIBIT logic gate was fabricated using this reversible nature of the sensor complex. Additionally, the chemosensor ANB shows a novel aggregation-induced enhanced emission phenomenon, where the aggregate hydrosol of ANB shows enhance emission intensity. [GRAPHICS] .

Automated summary

A fluorescent chemosensor, 3-(Anthracen-2-yliminomethyl)-benzene-1,2-diol (ANB), was synthesized by condensation of 2-aminoanthracene and 2,3-dihydroxybenzaldehyde, and characterized using H-1-NMR, FT-IR, and Mass spectroscopic techniques. The ANB probe showed efficient 'turn-on' fluorescence for selective detection of Al3+ ion in an aqueous solution. The chemosensor exhibited a 27-fold enhancement of emission intensity in the presence of Al3+ ion.