The anion-sensing properties of N-(4-nitrophenylazo)-Nâ²-propyl thiourea chromoionophores have been investigated as free agents in bulk solution and following immobilization on a solâgel silica film. In addition, the effect of a variety of organic spacers on the immobilized chromoionophores was examined. The binding constants of free chromoionophores with anions were greater than those of the corresponding immobilized chromoionophores in acetonitrile solution and their binding constants revealed a trend were CH3CO2â > H2PO4â > Clâ. However, the use of an organic spacer with an immobilized chromoionophore can change the binding constants of anions. An octadecyl group spacer, for example, led to an increase in the difference between the binding constants of the acetate ion and other anions and also enhanced selectivity for the acetate ion.
N-(4-
硝基苯偶氮)-N'-(丙基)
硫脲染料离子探测剂的阴离子感知特性已在自由状态的体相溶液中以及固定在溶胶-胶质
硅酸盐薄膜上的状态下进行了研究。此外,还考察了各种有机间隔物对固定
染料离子探测剂的影响。自由
染料离子探测剂与阴离子的结合常数在
乙腈溶液中大于相应固定
染料离子探测剂的结合常数,并且其结合常数显示出趋势为 CH3CO2⁻ > H2PO4⁻ > Cl⁻。然而,使用有机间隔物的固定
染料离子探测剂可以改变阴离子的结合常数。例如,
十八烷基间隔物导致
醋酸根离子与其他阴离子的结合常数之间的差异增加,同时增强了对
醋酸根离子的选择性。