Selective and unusual fluoride ion complexation by a steroidal receptor using OH ... F- and CH ... F- interactions:: A new motif for anion coordination?

A novel cholaphane has been synthesized from a naturally occurring bile acid in just two steps. It has an ability to bind two fluoride ions selectively utilizing the glycolate motif in chloroform. This inside-out cyclodextrin analogue encapsulates fluoride through O-(HF-)-F-... and C-(HF)-F-...- interaction.