“Hooked-on” Calix[8]arenes: A (H2O)10 Cluster with an Unprecedented Structure

Calix[8]arene was crystallized at the THF/water interface in the presence of K 2 CO 3 to yield a one-dimensional channel structure. Between two neighboring macrocyclic ligands, two potassium ions are bridged via water molecules, whereas the next two calix[8]arenes are “sandwiching” a water cluster made of 10 water molecules. The water cluster and the potassium dimer are further coordinated by THF molecules. The channel is thus formed by the calix[8]arene and the THF ligands, their oxygen atoms pointing inward.