Immobilization of azacrown ligand onto a fluorophore

Geometric immobilization of azacrown ligand onto a fluorophore is expected to change their binding properties toward ion discrimination. An immobilized azacrown ligand 1 onto anthracene fluorophore senses Al(III), Cu(II) and Ga(III) in ethanol among the metal ions examined. In 100% aqueous solution, ligand 1 shows large CHEF effects with Al(III) and Ga(III) and large CHEQ effect with Hg(II). By comparison, non-immobilized azacrown ligand 2 showed large CHEF effects with Al(III), Ce(III), Ga(III), La(III) and Zn(II) in ethanol.