A highly selective colorimetric sensor to Fe3+ and Co2+ in aqueous solutions

作者:Wang Haiping; Li Juan; Yao Denghui; Gao Qun; Guo Fengqi*; Xie Puhui
来源:Research on Chemical Intermediates, 2013, 39(6): 2723-2734.
DOI:10.1007/s11164-012-0793-5

摘要

Five aromatic azo dyes with hydroxyl groups (1-5) were designed and synthesized by coupling reactions. The relationships between structures of the compounds and the spectroscopic properties were investigated. The absorption spectra of these compounds upon titration with K+, Ca2+, Al3+, Mg2+, Ni2+, Mn2+, Cd2+, Cr3+, Fe3+, Cu2+, Zn2+, Co2+, Hg2+, and Pb2+ ions in neutral aqueous solutions were reported. The results are coincident with the calculation results using the density functional theory method. The high selectivity, excellent water solubility and simple synthetic process make 1-[(2-Hydroxyl)phenylazo]-2-naphthol (5) a potential sensor for sensing Fe3+ and Mn2+ with the naked eye. 1-[(2-hydroxyl)phenylazo]-2-naphthol-6-sulfonic acid (3) shows high selectivity for the colorimetric detection of Fe3+ and Co2+ among the tested metal ions. The detection limitations of 3 for determining Co2+ and Fe3+ were calculated to be 2.8 x 10(-7) and 5.6 x 10(-7) mol/L, respectively.

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