AbstractMolecular receptors for organic molecules are described in which calix[4]arene is used as amolecular platformrather than for itscavity. This is illustrated by the synthesis of a receptor for barbiturates, a calix[4]arene in a cone conformation containing two diaminotriazine moieties at the upper rim. This receptor(9)forms a molecular cleft in which phenobarbital complexes by hydrogen bonding both triazine rings. The association constantKis 520 M1, when the self‐association of the barbiturate is taken into accoun