A novel cyclometalated Ir(III) complex based luminescence intensity and lifetime sensor for Cu2+

作者：Shen, Wei; Qi, Zhengjian^*; Yan, Liqiang; Tian, Wenwen; Cui, Xia; Yao, Hongtao; Sun, Yueming^*

来源：RSC Advances, 2016, 6(20): 16482-16488.

DOI：10.1039/c5ra27189d

• IRIDIUM(III) DIIMINE COMPLEXES
• TRANSITION-METAL IONS
• FLUORESCENT SENSOR
• RUTHENIUM(II) COMPLEX
• HIGH SELECTIVITY
• SULFIDE ANION
• ZN2+ IONS
• CHEMOSENSOR
• PHOSPHORESCENCE
• RECOGNITION

We report the synthesis and characterization of two luminescent cyclometalated Ir(III) complexes [Ir(dfppy)2(bpy-DPA)]PF6 (Ir-1) and [Ir(dfppy)2(bpy-BiDPA)]PF6 (Ir-2), where dfppy, bpy-DPA and bpy-BiDPA represent 2-(2,4-difluorophenyl) pyridine, N-([2,20-bipyridine]-4-yl)-2-(bis(pyridin-2-ylmethyl) amino) acetamide and N,N'-([2,2'-bipyridine]-4,4'-diyl) bis(2-(bis(pyridin-2-ylmethyl)amino)acetamide), respectively. Their photophysical properties and sensing properties towards various metal ions were investigated at room temperature. The two complexes both possessed good photophysical properties, and Ir-2 had quite a high quantum yield (93.83%) and a long lifetime (101.17 mu s), which is impressive among Ir(III) complexes. Ir-2 exhibited both high selectivity and sensitivity towards Cu2+ over other metal ions. The Job curve and mass spectra suggested the formation of a 1 : 2 bonding mode between Ir-2 and Cu2+. The photoluminescence (PL) intensity quenching curve indicated that Ir-2 could enable rapid and reversible detection of Cu2+ with a low detection limit of 0.85 ppb (13 nM). Furthermore, a linear relationship could be observed between the PL lifetime value of Ir-2 and the concentration of Cu2+ ions in the range of 0-8 mu M. These results suggested that Ir-2 might have use as not only a promising photoluminescence intensity sensor, but also a promising lifetime sensor for Cu2+ in aqueous solution.

• 出版日期2016
• 单位东南大学