Organic and Polymer Synthesis Laboratory, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620 015, India.
J Mol Recognit. 2013 Jun;26(6):259-67. doi: 10.1002/jmr.2268.
A series of novel, highly sensitive, and selective azo-based anion sensors 1-3 have been designed and synthesized from the condensation reaction between 4-amino azo benzene and three different aldehydes. The structure of the sensors 1-3 were confirmed by IR, HRMS, (1)H NMR, and (13)C NMR spectroscopic methods. Colorimetric naked-eye analysis revealed the anion detection by receptors 2 and 3 as color changes from yellow to pink and yellow to orange, respectively. Anion sensing ability of all receptors was further investigated by (1) H NMR titration, UV-vis experiment, and fluorescence titration. UV-vis measurements highly indicate the selective recognition of fluoride and acetate ions in 9:1 dimethyl sulfoxide-H2O (v/v) for receptors 2 and 3. Binding constant value showed among all receptors, receptor 3 has strong affinity toward F(-) and AcO(-) in semi-aqueous medium, which is due to the presence of chromogenic signaling unit in it. The F(-) ion detection property of receptor 2 in organic medium was also extended in the real sample like toothpaste.
已经设计并合成了一系列新型的、高灵敏度和选择性的基于偶氮的阴离子传感器 1-3，它们是通过 4-氨基偶氮苯和三种不同的醛之间的缩合反应得到的。传感器 1-3 的结构通过 IR、HRMS、(1)H NMR 和 (13)C NMR 光谱方法得到确认。比色肉眼分析显示，受体 2 和 3 通过颜色从黄色变为粉红色和黄色变为橙色来检测阴离子。通过 (1)H NMR 滴定、UV-vis 实验和荧光滴定进一步研究了所有受体的阴离子传感能力。UV-vis 测量高度表明，受体 2 和 3 在 9:1 的二甲基亚砜-H2O（v/v）中对氟离子和乙酸根离子具有选择性识别。结合常数值表明，在所有受体中，受体 3 在半水相中对 F(-)和 AcO(-)具有很强的亲和力，这是由于其存在显色信号单元。受体 2 在有机介质中对 F(-)离子的检测性能也在牙膏等实际样品中得到了扩展。
