2,5-Thienylene-Strapped [26]Hexaphyrin as Multifunctional Chemosensor for Hg 2+ , Cu 2+ , and F - Ions.

The sensing behavior of 2,5-thienylene-bridged tetrakis(2,6-dichlorophenyl)-[26]hexaphyrin (2) towards various metal ions and anions were investigated by UV-vis and fluorescence spectroscopies. Using this strapped hexaphyrin (2), the molecular sensor displayed highly selective and sensitive colorimetric responses to Cu 2+ and Hg 2+ in MeOH/THF. The spectral changes are distinctive enough in the visible region of the spectrum to enable naked-eye detection. The detection limits of Cu 2+ and Hg 2+ using this chemo-sensor in a mixed MeOH/THF solution were 1.978 and 1.283 μM, respectively, and 1.052 μM for F - in dichloromethane. Chemosensor 2,5-thienylene strapped [26]hexaphyrin (2) shows absorption responses both a 1 : 1 molecular ratio for 2 interacting with Cu 2+ and Hg 2+ and a 1 : 2 ratio between 2 and F - ions.