In 1877, a German chemist synthesized a white crystalline powder for the first time in the laboratory - glycoluril. At the time, the chemical world was immersed in the golden age of organic synthesis, and the birth of glycoluril did not cause much of a stir. However, what really brought it into the spotlight was a "fortuitous accident" 28 years later. In 1905, Behrend's research group condensed glycoluril with formaldehyde under concentrated sulfuric acid and obtained a product with a peculiar structure, but due to the limitations of analytical techniques at the time, its precise structure could not be identified. This fog of mystery was not dispelled until nearly 80 years later by modern crystallography: the product turned out to be a cage-like macromolecule formed by multiple glycoluril units linked through methylene bridges. Because its shape resembled a pumpkin (Cucurbitaceae), it was named cucurbituril.
From then on, glycoluril transformed from an obscure heterocyclic compound into a key "building block" on the stage of supramolecular chemistry. More than a century later, glycoluril and its derivatives are now shining brightly in numerous fields such as coatings, water treatment, electronic equipment, supramolecular recognition, drug controlled release, and molecular catalysis. A "veteran molecule" born in 1877 has embraced its moment in the spotlight in the 21st century.