硝基苯偶氮酚衍生物应用于阴离子识别

Application of p-Nitrobenzene Azophenol Derivatives to Anion Recognition

设计合成了对硝基苯偶氮酚类化合物,比较了α-萘酚、8-羟基喹啉和苯酚等3类偶氮硝基苯衍生物的吸收光谱及其阴离子配合物稳定性的差异.研究表明,α-萘酚、8-羟基喹啉和苯酚等3个含酚羟基的偶氮硝基苯化合物均可识别阴离子客体,产生显著的光谱和颜色变化,实现了裸眼检测阴离子.就同一主体分子而言,主-客体配合物的稳定常数大小依次为AcO->F->H2PO-4>Cl-,与阴离子碱性强弱顺序一致;而不同主体分子对同一阴离子亲和力的大小顺序为:α-萘酚>8-羟基喹啉>苯酚,亲和力的大小与主体分子中电子供体的给电子能力和主体分子共轭体系的大小相关.

Compounds based on p-nitrobenzene azophenol were designed and synthesized. The properties of absorption spectra and association constants of complexes between hosts and anions were investigated and compare. The results indicated that the three compounds, 1-naphthol-4-azo-4′-nitrobenzene, 8-hydroxyl-quinoline-5-azo-4′-nitrobenzene and 1-phenol-4-azo-4′-nitrobenzene, could act as efficient chromogenic reagents for the anion sensing. Upon addition of various anions, the spectral profile and color of the solution of hosts changed significantly. The affinity of hosts for anions was measured by UV-Vis spectroscopic titration experiments. For the same host, the association constants followed the order of AcO^-〉F^-〉H2PO^-4〉C1^-, which was in agreement with the basicity order of anions. And for the same anions such as AcO^-, the association constants followed the order of 3（α-naphthol）〉2（8-hydroxyl-quinoline）〉l（phenol）, which is attributed to electronic withdrawing effect of substituents and the conjugated system of host compounds.