The influence of amino substituents on the signal‐output, selectivity, and sensitivity of a hydroxyaromatic 1,2,3‐triazolyl chemosensor for anions—A structure–property relationship investigation

The influence of strongly electron donating amino groups on a hydroxyaromatic 1,2,3‐triazolyl anion chemosensor was investigated with spectroscopic studies (ultraviolet‐visible [UV‐vis], fluorescence, and nuclear magnetic resonance [NMR]) and computational analyses. This work focused on 2‐, 3‐ and 4‐amino derivatives of the parent molecule, 2‐(4‐phenyl‐1H‐1,2,3‐triazol‐1‐yl)phenol (PTP). The effect on signal‐output, selectivity, sensitivity, and the mechanism of response was explored. In all cases, the incorporation of the amino group enhances fluorescence during anion detection while retaining key properties (the receptor site, a blue‐fluorescent response, and the ability to detect F−, H2PO4−, and AcO−—strongest response to F−). Specifically, sensitivity to F− is impacted by the amino group's location. The 2‐amino is most responsive to F−, more than PTP and the other amino regioisomers. Results from this work are important for developing predictive, structure‐signal tuning models, which will be used in the targeted design of sensors based on the PTP scaffold.