Resorcin[4]arene-based anion receptors with four phenylurea substituents

Cavitand-based anion receptors were developed by the introduction of four phenylurea moieties on the upper rim of a resorcin[4]arene. Their binding properties for various anions were investigated in DMSO-d6 using 1H NMR spectroscopic methods, and the high 1:1 binding affinity for carboxylates was observed due to hydrophobic as well as charge-dipole interactions between host and guest.