Cucurbit[n]urils: from mechanism to structure and function

This feature article details some of the unusual recognition properties of the cucurbit[n]uril family (CB[n]) of molecular containers. It discusses the mechanism of CB[n] formation, which proceeds from glycolurilviamethylene bridged glycoluril oligomers, along with descriptions of the structures and recognition properties of some kinetically stable macrocyclic intermediates along the way. These partially formed CB[n]-type receptors known as nor-seco-CB[n] display intriguing properties such as chiral recognition, homotropic allostery, and function as aldehyde reaction cucurbituril synthons.