A novel HBT-based Schiff base for colorimetric detection of aluminum: Synthesis, characterization, spectral and DFT computational studies

A novel Schiff base L was easily synthesized by the condensation reaction of 2-aminophenol and p-hydroxyphenylbenzothiazole (p-HBT) and could be used for detection of aluminum in ethanol as well as in aqueous solution. Among the detected metal ions, only Al3+ ion can induce a significant enhancement in fluorescence intensity. The lowest detection limit and the dissociation constants K-d for Al3+ are determined to be 8.24 x 10(-9) M and 3.00 x 10(-5) M, respectively. In addition, the binding details of L-Al3+ complex were investigated by means of infrared spectra, H-1 NMR titration and DFT computational studies, implying the fluorescence intensity enhanced by the inhibition of the ESIPT process in L, and further the formation of a large pi-electron conjugation system. (C) 2013 Elsevier B.V. All rights reserved.