title: A highly selective sulfur-free iridium(III)-complex-based phosphorescent chemidosimeter for detection of mercury(II) ions.
abstract: A neutral phosphorescent coordination compound bearing a benzimidazole ligand, Ir(pbi)(2)(acac) (Hpbi = 1,2-diphenyl-1H-benzo[d]imidazole; Hacac = acetylacetone), is demonstrated to be the first example of a sulfur-free iridium complex for the detection of Hg(2+) cations with high selectivity and sensitivity. Ir(pbi)(2)(acac) shows a multisignaling response towards mercury(II) ions through UV-vis absorption, phosphorescence and electrochemistry measurements. Upon addition of Hg(2+) ions, solutions of this complex change from yellow to colorless, which could be observed easily by the naked eye, while its phosphorescence turns from bright green (λ(PLmax) = 520 nm) into faint skyblue (λ(PLmax) = 476 nm), and the detection limit is calculated to be 2.4 × 10(-7) mol L(-1). (1)H NMR spectroscopic titration as well as ESI-MS results indicate that the decomposition of Ir(pbi)(2)(acac) in the presence of Hg(2+) through rupture of Ir-O bonds is responsible for the significant variations in both optical and electrochemical signals.
authors.affiliation: College of Chemistry, Sichuan University, Chengdu, 610064, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Zeng
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.forename: Jun
authors.initials: J
authors.lastname: Dai
authors.forename: Huiqin
authors.initials: H
authors.lastname: Sun
authors.forename: Zhiyun
authors.initials: Z
authors.lastname: Lu
authors.forename: Ming
authors.initials: M
authors.lastname: Li
authors.forename: Qing
authors.initials: Q
authors.lastname: Jiang
authors.forename: Yan
authors.initials: Y
authors.lastname: Huang
mesh_terms: D001562:Benzimidazoles / Q000737:chemistry; D056831:Coordination Complexes / Q000737:chemistry*; D004563:Electrochemistry; D004785:Environmental Pollutants / Q000032:analysis*; D007495:Iridium / Q000737:chemistry*; D049449:Luminescence; D008628:Mercury / Q000032:analysis*
chemical_list: D001562:Benzimidazoles; D056831:Coordination Complexes; D004785:Environmental Pollutants; D007495:Iridium; C031000:benzimidazole; D008628:Mercury