Cationic iridium(III) complex containing both triarylboron and carbazole moieties as a ratiometric fluoride probe that utilizes a switchable triplet-singlet emission.
A novel cationic Ir(III) complex [Ir(Bpq)(2)(CzbpyCz)]PF(6) (Bpq=2-[4-(dimesitylboryl)phenyl]quinoline, CzbpyCz = 5,5'-bis(9-hexyl-9H-carbazol-3-yl)-2,2'-bipyridine) containing both triarylboron and carbazole moieties was synthesized. The excited-state properties of [Ir(Bpq)(2)(CzbpyCz)]PF(6) were investigated through UV/Vis absorption and photoluminescence spectroscopy and molecular-orbital calculations. This complex displayed highly efficient orange-red phosphorescent emission with an emission peak of 583 nm and quantum efficiency of Phi=0.30 in dichloromethane at room temperature. The binding of fluoride ions to [Ir(Bpq)(2)(CzbpyCz)]PF(6) can quench the phosphorescent emission from the Ir(III) complex and enhance the fluorescent emission from the N--N ligand, which corresponds to a visual change in the emission from orange-red to blue. Thus, both colorimetric and ratiometric fluoride sensing can be realized. Interestingly, an unusual intense absorption band in the visible region was observed. And the detection of F(-) ions can also be carried out with visible light as the excitation wavelength. More importantly, the linear response of the probe absorbance change at lambda=351 nm versus the concentration of F(-) ions allows efficient and accurate quantification of F(-) ions in the range 0-50 microM.
Xu
Wen-Juan
WJ
Jiangsu Key Laboratory for Organic Electronics & Information Displays and Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210046, China.
Liu
Shu-Juan
SJ
Zhao
Xin-Yan
XY
Sun
Shi
S
Cheng
Shan
S
Ma
Ting-Chun
TC
Sun
Hui-Bin
HB
Zhao
Qiang
Q
Huang
Wei
W
D001896:Boron Compounds / Q000737:chemistry*; D002227:Carbazoles / Q000737:chemistry*; D002412:Cations / Q000737:chemistry*; D018360:Crystallography, X-Ray; D005459:Fluorides / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D049408:Luminescent Agents / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*
D001896:Boron Compounds; D002227:Carbazoles; D002412:Cations; D008024:Ligands; D049408:Luminescent Agents; D009942:Organometallic Compounds; C041514:carbazole; D007495:Iridium; D005459:Fluorides