RESUMO
A new macrocyclic chemosensor containing two naphthalene fluorophores has been synthesized. The fluorescent properties of this receptor has been studied in the presence of various metal ions such as Na(+), Ag(+), Cr(3+), Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+) and Pb(2+). When increasing concentrations of Zn(2+) ions were introduced, the emission of L was drastically increased (EFE = 4.34). This special change was not observed when other metal ions were used; such highly selective fluorescent response indicates that this receptor can easily discriminate Zn(2+) ions from other similar species. Model calculations at DFT level further suggest the possible interaction mode, and relatively steric position between the host and guest also influence the optical response.
