【摘要】 应用吸收光谱滴定法研究了茜素与阴离子间的识别行为,比较了受体分子结构对阴离子配合物稳定性的影响。研究结果表明:在乙腈中,茜素通过氢键与Fˉ和AcOˉ分别形成 12和 11型稳定的阴离子配合物,在长波长 563nm和 553nm处分别出现电荷转移吸收带,溶液由无色变为紫红色或浅紫色,其它的阴离子如H2PO4ˉ,HSO4ˉ,ClO4ˉ,Clˉ及Brˉ等未引起明显的光谱及溶液颜色的变化。同时考察了 2, 4-二羟基苯甲酸和 3, 4-二羟基苯甲酸对阴离子的识别作用,发现:Fˉ对上述两个化合物吸收光谱影响相似,无明显差异;而AcOˉ对两者的光谱影响差别较大。因此,我们认为茜素对Fˉ和AcOˉ具有选择性识别作用取决于阴离子的碱性和主体分子的空间结构。更多还原

【Abstract】 A selective colorimetric assay for fluoride and acetate anion based on alizarin was developed.The effect of hydroxy configuration to anionic complex formation was investigated by UV-vis spectra titration.Results indicated that 1:2 complex between alizarin and fluoride was formed in acetonitrile,however,1:1 complex formed between alizarin and acetate.In the presence of fluoride or acetate,a new Absorption band appeared peaked at 563 nm and 553 nm respectively and the solution of alizarin turned from yellow to purple.However,no detectable color changes were observed in the present of other anions such as dihydrogen phosphate,chloride,bromate and hydrogen sulfate.Absorption spectra properties between the control compounds (3,4-dihydroxybenzoic acid and 2,4-dihydroxybenzoic acid) and anions were investigated.In conclusion,alizarin was found to selectively sense fluoride and acetate, this is attributed to the basicity of anions and configuration of receptor.更多还原