Novel colorimetric phosphorescent chemodosimeter for Hg2+ based iridium(III) complex with phosphonodithioate auxiliary ligand

A colorimetric phosphorescent iridium(III) complex chemodosimeter (Ir1) for Hg2+ has been prepared and confirmed by NMR, MS, and crystal data, which displays a high selectivity and antidisturbance for Hg2+ among relevant metal ions. The solution color changed from orange to light yellow as soon as 1 equiv of Hg2+ was added. Phosphorescent studies show that the luminescence intensity in 599 nm decreased to ca. 13%, while the luminescence intensity in 465 nm increased to ca. 217%. The ratio of Ir1 responding to Hg2+ was determined to be 1:1 by UV–vis absorption and phosphorescent emission measurements. Further study demonstrates the detection limit on phosphorescent response of the sensor to Hg2+ is down to 10−6 M range. The mechanism study shows that the interaction between the S atom of ancillary ligand and Hg2+ is responsible for the highly selective and sensitive phosphorescent senor for Hg2+.

A colorimetric phosphorescent chemodosimeter (Ir1) for Hg2+ has been prepared. The phosphorescent intensity in 599 nm decreased to ca. 13%, while the intensity in 465 nm increased to ca. 217%. The ratio of Ir1 responding to Hg2+ was determined to be 1:1 by UV–Vis absorption and luminescence measurements. Figure optionsDownload as PowerPoint slideHighlights
► The chemical structure of new iridium(III) complex has been characterized by single-crystal X-ray analysis.
► This complex can serve as a chemodosimeter for Hg2+ with ratiometric and naked-eye detection.
►  New chemodosimeter has a highly selective UV–vis and PL response for Hg2+. 
►  New chemodosimeter has a 1:1 interaction with Hg2+.