Two thread-shaped cations, pyridinium nicotinamide and imidazolium, as their chloride and hexafluorophosphate salts, were studied with regards to complexation with hydrogen-bonddonating acyclic and macrocyclic ligands. In the latter case, the cations form pseudorotaxanes templated by the chloride anion but not hexafluorophosphate. This formation is a function of the coupling of ion-pairing between the cation and chloride anion and subsequent recognition of the anion by the macrocyclic diamide, which provides the driving force for interpenetration. We propose that this anion template principle is a general method for the construction of pseudorotaxanes and could be applied to other cationic threads, anions, and macrocyclic species.
Three fluorescence sensors based on naphthoquinoneimidazole and boronic acid (A-D-A system) have been developed with high selectivity for cyanide in water. The fluorescence band at 460 nm was switched on upon substitution of cyanide on sensors in the CTAB micelle.
Calix[4]arene derivatives containing amide ferrocene units at the wide rim and ethyl ester groups at the narrow rim, L1-L3, were synthesized and their anion binding and sensing properties were investigated. It was found from (1)H NMR titrations that L1-L3 were able to bind selectively with carboxylate anions. Moreover, cyclic voltammetry and square wave voltammetry showed that L1-L3 were able to act as electrochemical sensors for carboxylate anions. [structure: see text]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.