Eu3+ chelate with phenanthroline derivative gives selective emission responses to Cu(II) ions

Two novel ternary europium(III) complexes (Eu-1 and 2) based on modified phenanthroline ring have been successfully synthesized and give characteristic purple red emissions. The complex with 4-substituted carboxyl group has been proved to act as a selective luminescence quencher for copper(II) ions, as shown by the on/off switch phenomenon and the smart responsive changes in the UV-vis region (detection limit up to 0.5 mu M). The preliminary data imply that Eu-1 could be applicable as a potential fluorescent sensor for detection of copper(II) ions. (C) 2010 Elsevier B.V. All rights reserved.