Synthesis and silver ion complexation behavior of fluoroionophores containing a benzothiazolyl group linked to an N-phenylpolythiazaalkane moiety

Cyclic and acyclic polythiazaalkane derivatives bearing a benzothiazolyl group as a fluorophore have been synthesized. The protonation and the metal ion complexation behavior were studied in a 1,4-dioxane–water (52/48 v/v) solution by spectrophotometry and/or spectrofluorometry. The changes in the absorption spectra (blue shift and hypochromic effect) and the fluorescence emission spectra (quenching) were observed by the addition of Ag+ ion selectively. On complexation with the Ag+ ion, the degree of the spectral changes of the benzothiazole derivatives is dependent on the extent of the interactions of the complexed Ag+ ion with the nitrogen atom of the polythiazaalkane moiety and with the benzothiazolylphenyl moiety. The complexation and the protonation behavior of the benzothiazole derivatives were investigated using 1H NMR spectroscopy.