Synthesis, X-ray structure, and anion-binding properties of a cryptand-like hybrid calixpyrrole.

The novel cryptand in/out-3, containing two tripyrrolemethane units bridged by three 1,3- diisopropylidenbenzene arms, was readily synthesized by a convergent three-step synthesis. It binds fluoride by inclusion with excellent selectivity with respect to a number of other tested anions. The structure of the free receptor and that of its fluoride complex were investigated in solution by NMR spectroscopy.