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

The compound I with preorganized structure was synthesized, and its absorpt ion and fluorescence spectra in the presence of dicarboxylate anion were st udied. The results showed that the emission of compound 1 at 380 nm could b e quenched via addition of dicarboxylate anion, and a structureless red-shi ft emission band at 500 nm appeared simultaneously. These phenomena could b e caused by the formation of the complex of compound I and dicarboxylate an ion. According to the results of fluorescence spectra and H-1-NMR, the bind ing constant. of pimelate with compound 1 has the largest value, owing to t he most suitable conformation of compound 1 for pimelate.