Cavitand-Based Supramolecular Sensors for the Detection of Acetates

A series of eight new cavitand receptors were prepared in an effort to obtain selective mass sensors for the detection of acetates. The desired synergy between the cavity inclusion and H-bonding was obtained introducing a carboxylic residue on one of the bridging groups, which delimitate the cavity at the upper rim. The orientation of the COOH group inward or outward (cavitands 3-in and 4-out) determines a different ability to detect acetates according to their chain length. Acetate versus ester discrimination has been obtained by extending the cavity rim using a 4-chloro-phenoxy substituent in the inward position (cavitand 8-out).