Colorimetric recognition of acetate anions in aqueous solution using charge neutral azo derivatives

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2012-02, Vol.86, p.437-442
• Main Authors: Huang, Weiwei, Li, Yaping, Lin, Hai, Lin, Huakuan
• Format: Article
• Language: English
• Subjects: Acetate; Anion recognition; Azo derivative; Colorimetric; Naked-eye
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2011.10.064

[Display omitted] ► The synthesis process of the two receptors is simple and easy. Thus, it made them in practical use possible. ► The color changes induced by anions can provide a way of detection by ‘naked-eye’. Receptor 1 and 2 recognizing acetate could occur not only in DMSO solution, but also in DMSO/H 2O (9:1, v/v) solution. ► Receptors 1 and 2 can recognize acetate is of great importance, because acetate is an important biological molecule. Two novel highly sensitive colorimetric acetate anion receptors: 4-phenylazo-2-hydroxy-benzaldehyde 4-nitrophenylhydrazone ( 1) and 4-phenylazo-2-hydroxy-benzaldehyde 2,4-dinitrophenylhydrazone ( 2) based on azo derivative have been designed and synthesized. UV–vis experiments show that receptor 1 and receptor 2 can selectively recognize acetate in DMSO and even in 9/1 DMSO/H 2O (v/v) mixtures. Meanwhile the color changes induced by anions can provide a way of detection by ‘naked-eye’. The further insights to the nature of interactions between receptor 1, 2 and AcO − have been investigated by 1H NMR titration experiments.