Noncovalent Tailoring of the Binding Pocket of Self-Assembled Cages by Remote Bulky Ancillary Groups

The binding properties of a self-assembled coordination cage were subtly tuned by ancillary groups on the metal corners of the cage. Since the bulky mesityl groups of the ligand hang over the cage cavity, the effective cavity volume is reduced. Due to the tighter guest packing inside the shrunken cavity, smaller guests were efficiently bound and guest motion was restricted even at high temperatures.