A highly selective chemosensor for mercury(II) cations based on cyclometalated iridium(III) complex

A cyclometalated iridium(III) complex, Ir(dpci)2(dtc) (Ir1, dpci = 3,4-diphenylcinnoline, dtcH = diethyl dithiocarbamic acid), was synthesized from the reaction of the iridium complex [Ir(dpci)2(Cl)]2 and dtcNa in methanol/CH2Cl2, and characterized by FT-IR, 1H NMR and mass spectroscopies. The photoluminescence spectrum of Ir1 shows emission maximum at 686 nm with a lifetime of 0.77 μs and PL quantum yields is ca. 0.021. Moreover, [Ir(dpci)2(dtc)], containing a dithiocarbamate ancillary ligand, can serve as a highly selective turn-on chemodosimeter for Hg2+, which is associated with the dissociation of the dithiocarbamate ancillary ligand from the complex.

Graphical abstractA cyclometalated iridium(III) complex Ir1 was synthesized and characterized. The photoluminescence spectrum of Ir1 shows emission maximum at 686 nm with a lifetime of 0.77 μs. Moreover, Ir1 containing a dithiocarbamate ancillary ligand, can serve as a highly selective chemodosimeter for Hg2+, which is associated with the dissociation of the dithiocarbamate ancillary ligand from the complex.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A “turn-on” chemosensor for Hg2+ detection was reported. ► Organoiridium(III) dithionate complex was firstly used for Hg2+ detection. ► New chemosensor have a highly selective UV–Vis and PL response for Hg2+. ► New chemosensor has a 1:1 interaction with Hg2+.