Silver ion shuttling in the trimer-mimic thiacalix[4]crown tube.
Novel 1,3-alternate calix-thiacalix[4]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 thiacalix[4]crown-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 (1)H NMR spectrosocpy. Variable-temperature (1)H NMR studies for the trimeric thiacalix[4]crown-6 encapsulating the silver ion revealed that the Ag(+) ion oscillates through the central thiacalix spacer with the aid of cation-pi interactions.
Kim
Sung Kuk
SK
Department of Chemistry, Institute of Nanosensor and Biotechnology, Dankook University, Seoul 140-714, Korea.
Lee
Jae Kwang
JK
Lee
Seoung Ho
SH
Lim
Mi S
MS
Lee
Soon W
SW
Sim
Wonbo
W
Kim
Jong Seung
JS