Synthesis Of A Novel Macrocyclic Compound Benzourils And Investigation Of Its Host-guest Interaction

A new macrocyclic compound,benzo[3]uril 1,was synthesized in a facile way,and displayed a unique fluorescence response upon recognition and binding of Cu2+,Fe3+,F-,and acetate.1H NMR spectra confirmed that binding occurs through hydrogen bonds between hydroxyl groups on the benzo[3]uril 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 spectroscopy suggest the carboxyl groups of benzo[3]uril coordinate metal cations Cu2+ and Fe3+.To investigate the substituent effect on benzo[3]urils binding ions,a series of benzimidazolone monomers were subjected to the cyclozation,and the reaction conditions including acidity,solvent,reaction time were optimized,finally,two new members(benzo[3]uril 3 and benzo[3]uril 4)were achieved with a portable synthetic route and high yield.Benzo[3]uril 3 shows the same recognition nature as benzo[3]uril 1.The interaction between the host and inorganic ions was confirmed by 1H NMR and fluorescence spectrophotometry.Benzo[3]uril 4 bearing carboxylic groups exhibits the activity of recognition towards Cu2+,Fe3+,F-and acetate,and further binding to ion pairs.