Switchable Metal-Ion Selectivity in Sulfur-Functionalised Pillar[5]arenes and Their Host-Guest Complexes
Issued Date
2023-01-01
Resource Type
ISSN
18614728
eISSN
1861471X
Scopus ID
2-s2.0-85177737335
Journal Title
Chemistry - An Asian Journal
Rights Holder(s)
SCOPUS
Bibliographic Citation
Chemistry - An Asian Journal (2023)
Suggested Citation
Todee B., Sanae P., Ruengsuk A., Janthakit P., Promarak V., Tantirungrotechai J., Sukwattanasinitt M., Limpanuparb T., Harding D.J., Bunchuay T. Switchable Metal-Ion Selectivity in Sulfur-Functionalised Pillar[5]arenes and Their Host-Guest Complexes. Chemistry - An Asian Journal (2023). doi:10.1002/asia.202300913 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/91299
Title
Switchable Metal-Ion Selectivity in Sulfur-Functionalised Pillar[5]arenes and Their Host-Guest Complexes
Other Contributor(s)
Abstract
Nucleophilic substitution of pertosylated pillar[5]arene (P-OTs) with commercially available sulfur containing nucleophiles (KSCN, KSAc, and thiophenol), yields a series of sulfur-functionalised pillar[5]arenes. DLS results and SEM images imply that these pillararene macrocycles self-assemble in acetonitrile solution, while X-ray crystallographic evidence suggests solvent-dependent assembly in the solid state. The nature of the sulfur substituents decorating the rim of the pillararene controls binding affinities towards organic guest encapsulations within the cavity and dictates metal-ion binding properties through the formation of favorable S−M2+ coordination bonds outside the cavity, as determined by 1H NMR and fluorescence spectroscopic experiments. Addition of a dinitrile guest containing a bis-triazole benzene spacer (btn) induced formation of pseudorotaxane host-guest complexes. Fluorescence emission signals from these discrete macrocycles were significantly attenuated in the presence of either Hg2+ or Cu2+ in solution. Analogous titrations utilizing the corresponding pseudorotaxanes alter the binding selectivity and improve fluorescence sensing sensitivity. In addition, preliminary liquid-liquid extraction studies indicate that the macrocycles facilitate the transfer of Cu2+ from the aqueous to the organic phase in comparison to extraction without pillar[5]arene ligands.