View all references ] Their rigid conformation enables calixarenes to act as host molecules as a result of their preformed cavities. By functionally modifying the upper and/or lower rims, it is possible to synthesize their various derivatives with applications such as enzyme mimetics, [
![5,11,17,23-Tetranitro-25,26,27,28-tetrahydroxypentacyclo[19.3.1.13,7.19,13.115,19]octacosa-1(25),3,5,7(28),9,11,13(27),15,17,19(26),21,23-dodecaene Structure](https://image.chemsrc.com/caspic/247/109051-62-9.png)