title: Encapsulation of xenon by a self-assembled Fe4L6 metallosupramolecular cage.
abstract: We report (129)Xe NMR experiments showing that a Fe4L6 metallosupramolecular cage can encapsulate xenon in water with a binding constant of 16 M(-1). The observations pave the way for exploiting metallosupramolecular cages as economical means to extract rare gases as well as (129)Xe NMR-based bio-, pH, and temperature sensors. Xe in the Fe4L6 cage has an unusual chemical shift downfield from free Xe in water. The exchange rate between the encapsulated and free Xe was determined to be about 10 Hz, potentially allowing signal amplification via chemical exchange saturation transfer. Computational treatment showed that dynamical effects of Xe motion as well as relativistic effects have significant contributions to the chemical shift of Xe in the cage and enabled the replication of the observed linear temperature dependence of the shift.
authors: NMR Research Group, Centre for Molecular Materials, University of Oulu , 90014 Oulu, Finland.
authors: Juho
authors: J
authors: Roukala
authors: Jianfeng
authors: J
authors: Zhu
authors: Chandan
authors: C
authors: Giri
authors: Kari
authors: K
authors: Rissanen
authors: Perttu
authors: P
authors: Lantto
authors: Ville-Veikko
authors: VV
authors: Telkki