Recognition of linear dicarboxylate anions by the host with two naphthylurea groups

The compound I with preorganized structure was synthesized, and its absorption and fluorescence spectra in the presence of dicarboxylate anion were studied. The results showed that the emission of compound 1 at 380 nm could be quenched via addition of dicarboxylate anion, and a structureless red-shift emission band at 500 nm appeared simultaneously. These phenomena could be caused by the formation of the complex of compound I and dicarboxylate anion. According to the results of fluorescence spectra and H-1-NMR, the binding constant. of pimelate with compound 1 has the largest value, owing to the most suitable conformation of compound 1 for pimelate.