Benzo[3]urils and their Recognition to Metal Cations and Anions

A new macrocyclic compound, benzo[3]uril 1, was synthesized in a facile manner, and displayed a unique fluorescence response upon recognition and binding of Cu2+, Fe3+, F-, and acetate.([1]) HNMR (Nuclear Magnetic Resonance) spectra confirmed that binding occurs through hydrogen bonds between hydroxyl groups on the benzo[3]uril 1 and F- or acetate anions. The successful synthesis of benzo[3] uril 2 demonstrates that modification of this macrocycle is relative easy, and the absence of an interaction with anions further supports the importance of hydrogen binding between benzo[3]uril 1 to F(-)and acetate. Infra- red (IR) spectroscopy suggest the carboxyl groups of benzo[3]uril coordinate metal cations Cu2+ and Fe3+.