Crown ether styryl dyes: 21. Synthesis, spectral properties, and complex formation of trans-isomers of the chromogenic dithia-15(18)-crown-5(6) ethers

Article abstract of DOI:10.1007/BF02496129

Novel styryl dyes containing dithia-15(18)-crown-6(5)-ether moieties were synthesized. Their selective complex formation with Hg²⁺ and Ag⁺ ions was studied by ¹H NMR and electronic spectroscopy; the stability constants of the Ag⁺ complexes and the relative stability constants (in relation to benzodithia-18-crown-6) of the Hg²⁺ complexes were determined. The chemical shifts of the β,β′-protons in the CH₂S group change upon the complex formation in parallel with the logK₁ values of the complexes.