Cucurbituril


![Crystal structure of the CB[10]•CB[5]complex including a chlorine anion.[5]](/uploads/202501/07/Cucurbituril_gyroscope_AngewChemIntEd_2002_v41_p275_hires0904.png)
![Crystal structure of a host-guest complex with a p-xylylenediammonium bound within a cucurbit[6]uril reported by Freeman in Acta Crystallogr B, 1984, 382-387.](/uploads/202501/07/Cucurbit-6-uril_ActaCrystallB-Stru_1984_3820904.jpg)
Cucurbiturils are macrocyclic molecules made of glycoluril (=C4H2N4O2=) monomers linked by methylene bridges (-CH2-). The oxygen atoms are located along the edges of the band and are tilted inwards, forming a partly enclosed cavity. The name is derived from the resemblance of this molecule with a pumpkin of the family of Cucurbitaceae.