Ship in a breakable bottle: fluoride-induced release of an organic molecule from a Pr(III)-linked molecular cage

A 3-dimensional networked molecular cage, NMC-1, has been synthesized. This macrocycle-based framework was prepared from a solvothermal reaction involving a flexible organic building block, calix[4]pyrrole dibenzoic acid (H₂L), and Pr(NO₃)₃·6H₂O. A unique feature of NMC-1 is that it retains free calix[4]pyrrole molecules in the framework pores. Treatment with a fluoride anion source serves to destroy the network and allows release of the organic guest. The net result is a ‘molecular ship’ in a ‘breakable bottle’.