Colorimetric and luminescent bifunctional iridium(III) complexes for the sensitive recognition of cyanide ions

Two new cyclometalated iridium(III) complexes [(ppy)(2)Irppz]Cl (1) and [(ppy)(2)Irbppz]Cl (2) (where ppy = 2-phenylpyridine, ppz = 4,7-phenanthrolino-5,6:5,6-pyrazine, bppz = 2.3-di-2-pyridylpyrazine), were designed and synthesized. The structure of [(ppy)(2)Irppz]Cl was determined by single crystal X-ray diffraction. Their photophysical properties were also studied. This kind of complexes could coordinate with Cu2+, the photoluminescence (PL) of the complex was quenched, and the color changed from orange-red to green. The forming M-Cu (M: complexes 1 and 2) ensemble could be further utilized as a colorimetric and emission "turn-on" bifunctional detection for CN-, especially for complex 1-Cu2+ showed a high sensitivity toward CN- with a limit of diction is 97 nM. Importantly, this kind of iridium(III) complexes shows a unique recognition of cyanide ions over other anions which makes it an eligible sensing probe for cyanide ions. (C) 2016 Elsevier B.V. All rights reserved.