LAUSR

The coordination and sensing properties towards anions and transition metal ions of the simple novel fluorescent urea 1-(2aminophenyl)-3-(naphthalen-1)-yl)urea (L) were investigated in solution, and in the solid state. An electron donating amine group in the molecular skeleton of L decreased the acidity of the urea NHs that are usually deprotonated by basic anions and allowed for a good degree of affinity towards fluoride in DMSOd6-0.5%H2O. Moreover, the amine moiety acted as a further binding group for metal ions. Indeed, L was able to bind Zn both in solution and in the solid state, and to respond to the presence of this metal ion in MeCN with an enhancement of the fluorescence emission. Although solution studies evidenced the formation of a 1 :1 complex of L with Zn, complexes with a 2 :1 ligand-to-metal stoichiometry were isolated in the solid state. DFT calculations helped to clarify the stability reasons behind these results.