Phosphorescent chemosensor for Hg2+ based on an iridium(<scp>iii</scp>) complex coordinated with 4-phenylquinazoline and carbazole dithiocarbamate

A highly selective and colorimetric phosphorescent turn-on chemosensor for Hg2+ based on an iridium(III) complex Ir(pqz)2(cdc) (pqzH = 4-phenylquinazoline, Nacdc = sodium carbazole dithiocarbamate) was realized. The photograph of Ir(pqz)2(cdc)under ultraviolet light exhibited an emitting color change from red to yellow without and with Hg2+ in an acetonitrile (MeCN) solution, and it can also serve as a highly selective chemosensor for Hg2+ with naked-eye detection. Upon addition of a tetrahydrofuran (THF) solution of Hg2+, the dichloromethane (DCM) solution of Ir(pqz)2(cdc) gave a visual color change and significant luminescent quenching. When MeCN was added, a new emission peak at 562 nm emerged, which constituted a selective MeCN phosphorescent chemosensor.