A New Phosphorescent Cyclometalated Iridium(III) Complex for the Selective Detection of Silver(I) Ion

A new cyclometalated iridium(III) complex, Ir(ppz)2(dtp) (Ir1) (ppzH = 4-phenylphthalazinone, dtp = diethyl dithiophosphate), has been synthesized and characterized by single-crystal X-ray diffraction. The photoluminescence spectrum of Ir1 shows an emission maximum at 597 nm and its quantum yield is ca. 0.072. Complex Ir1 exhibits a strong and fast decrease of emission upon addition of Ag+ in aqueous media. The ratio of Ir1 responding to Ag+ was determined to be 1:1 by UV–Vis absorption and phosphorescent emission measurements. Complex Ir1 is a highly selective chemosensor for Ag+ over other transition metal ions.