Effect of the chromophoric unit on the complex formation properties in the crown ether containing styryl dyes

Abstract The benzo- and thieno-crown ethers containing styryl dyes have been designed and synthesized. The two series of the compounds were based on different combinations of the oxa- and azaoxa-crown ether fragments together with 2-benzovinyl- and thienylvinyl-benzothiazolium units. Their complexing, optical and electrochemical behaviors were characterized, while one and two dimensional NMR was employed to evaluate the structures of free and complexed ligands. The results of these studies showed that thienylvinyl derivatives display the poor ability for binding with metal ions through the crown ether moiety. The phenomenon was explained by the particular charge distribution in thienylvinyl derivatives preventing the interaction of chromophoric crown ethers with metal ions.