Experimental and theoretical studies of a colorimetric cu2+ chemosensor in aqueous solution

We have synthesized a new colorimetric chemosensor 3-(E)-4-(E)-phenyl imino methyl (pheny limino methyl) benzene-1,2-diol (1) based on a combination of 4-aminoazobenzene and 2,3-dihydroxybenzaldehyde. Receptor 1 showed a selective color change from colorless to yellow in the presence of Cu2+ in CH3CN/bis-tris buffer solution (v/v, 1:1), while other metal ions such as Al3+, Zn2+, Cd2+, Cu2+, Fe2+, Mg2+, Cr3+, Ag+, Co2+, Ni2+, Na+, K+, Ca2+, Mn2+ and Pb2+ had no influence. The detection limit (31 M) of 1 for Cu2+ was comparable to that (31 M) recommended by WHO in drinking water. The formation of 1-Cu2+ complex was proposed to be a 1:1 ratio, based on Job plot. Moreover, the sensing mechanism of Cu2+ by 1 was supported by theoretical calculations. Copyright © 2016 American Scientific Publishers All rights reserved.