Calixarene‐Based Nanoscale Coordination Cages

Molecular shuttlecocks: The introduction of tripodal ternary acids (red; see picture) to the cobalt/calixarene (green) systems led to the formation of four unprecedented calixarene-based nanoscale coordination cages through a [6+8] condensation. The overall periphery diameters of the nanocages ranged from 3.3 to 4.7 nm, and there were two sizes for the internal cavities (1.1 and 1.7 nm).