Novel 1,3-alternate calix-thiacalix crown trimers bearing crown-5 and crown-6 were prepared. As proven by X-ray diffraction, in a 1:2 mole ratio of ligand to metal ion, the Cs+ and K+ ions prefer to be encapsulated in the trimeric thiacalixcrown-6 and crown-5, respectively. On the contrary, the Ag+ ion was found to be entrapped in the central thiacalix spacer as a 1:1 complex confirmed by 1H NMR spectrosocpy. Variable-temperature 1H NMR studies for the trimeric thiacalixcrown-6 encapsulating the silver ion revealed that the Ag + ion oscillates through the central thiacalix spacer with the aid of cation-π interactions.
ASJC Scopus subject areas
- Organic Chemistry