Triazole‐bearing oligo(ethylene glycol)‐strapped zinc porphyrins as dual mode ion‐binding receptors

Abstract

AbstractA series of triazole‐bearing oligo(ethylene glycol)‐strapped zinc porphyrins (PZn4EG and PZn5EG) have been prepared as artificial ion‐binding receptors. Both PZn4EG and PZn5EG exhibit UV/Vis absorption changes in a solvent‐dependent manner upon titration with halides and alkali metal ions. In tetrahydrofuran, both PZn4EG and PZn5EG exhibit spectral shifts upon the addition of halide ions through axial coordination, whereas the absorption does not change upon the addition of alkali metal ions. On the other hand, in 10% MeCN/CHCl3, the UV/Vis absorption spectra of both PZn4EG and PZn5EG do not change upon the addition of an excess amount of halide ions; however, PZn4EG and PZn5EG show selective alkali metal ion‐binding properties in this solvent. PZn4EG and PZn5EG display dramatic color changes and spectral shifts upon the addition of Li+ and K+, respectively. Because of the dramatic color changes that occurred upon binding, the determination of alkali metal ions would be possible.