Influence of Different Substituents on Anion Binding Ability in Aromatic Hydroxyl Group Derivatives: Experiment and Theory

A series of new sensors (1, 2, 3 and 4) bearing aromatic hydroxyl group shows the strongest binding ability for AcO- by UV-vis, fluorescence, 1H NMR titrations and theoretical investigation. The sensitivity for AcO- can be tuned by electron push-pull properties of the substituents on the aromatic ortho position of the sensor. Especially, sensor 4 containing nitro group shows the best sensitivity. The excellent sensitivity of 4 for AcO- is attributed to the structure match of host-guest. In addition, the interacted process of host-guest accompanies color changes and can be used as new colorimetric chemosensors. Real life experimental result indicates that sensor 4 can be used to qualitatively detect the fluoride in toothpaste.