A new selective macroacyclic Schiff base fluorescent chemosensor containinghomopiperazine moiety for Al3+ ion

Al3+ ions existing in natural waters and most plants can enter the human body through foods and water.Sinceexcess or evendeficiency of aluminum ions can cause many pathological states, developing fluorescent chemosensors for detecting trace amounts of Al3+ has attracted increasing attention. a new chemosensor for Al3+ based on Schiff base with high sensitivity and selectivity was synthesized by condensation of a polyamine containing homopiperazine moiety with 2-hydroxybenzaldehyde, and characterized by IR, 1HNMR, 13CNMR and mass spectra (Scheme 1). After the addition of different metal ions such as Pb2+, Cr3+, Mn2+, Al3+, Ni2+, Co2+, Zn2+, Hg2+, Fe3+, Zn2+,Cd2+ only Al3+ could increase the fluorescence intensity of the H2L as a chemosensor(Fig.1 a). Also the fluorescence intensity of the chemosensor in ethanol solution was enhanced after the addition of Al3+ over other metal ions (Fig.1 b) [1,2].