title: A Convenient Approach To Synthesize o-Carborane-Functionalized Phosphorescent Iridium(III) Complexes for Endocellular Hypoxia Imaging.
abstract: The structure-property relationship of carborane-modified iridium(III) complexes was investigated. Firstly, an efficient approach for the synthesis of o-carborane-containing pyridine ligands a-f in high yields was developed by utilizing stable and cheap B10H10(Et4N)2as the starting material. By using these ligands, iridium(III) complexes I-VII were efficiently prepared. In combination with DFT calculations, the photophysical and electrochemical properties of these complexes were studied. The hydrophilic nido-o-carborane-based iridium(III) complex VII showed the highest phosphorescence efficiency (abs. ϕP =0.48) among known water-soluble homoleptic cyclometalated iridium(III) complexes and long emission lifetime (τ=1.24 μs) in aqueous solution. Both of them are sensitive to O2, and thus endocellular hypoxia imaging of complex VII was realized by time-resolved luminescence imaging (TRLI). This is the first example of applying TRLI in endocellular oxygen detection with a water-soluble nido-carborane functionalized iridium(III) complex.
authors: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China.
authors: Xiang
authors: X
authors: Li
authors: Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing, 210023, P.R. China.
authors: Xiao
authors: X
authors: Tong
authors: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China.
authors: Hong
authors: H
authors: Yan
authors: State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P.R. China.
authors: Changsheng
authors: C
authors: Lu
authors: Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing, 210023, P.R. China.
authors: Qiang
authors: Q
authors: Zhao
authors: Key Laboratory for Organic Electronics and Information Displays and Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing, 210023, P.R. China.
authors: Wei
authors: W
authors: Huang
mesh_terms: D001880:Boranes / Q000737:chemistry*; D015687:Cell Hypoxia / Q000502:physiology*; D007093:Imidazoles / Q000737:chemistry*; D007495:Iridium / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence
chemical_list: D001880:Boranes; D007093:Imidazoles; D008024:Ligands; D007495:Iridium; C049584:2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine
keywords: carboranes; imaging agents; iridium; phosphorescence; structure-property relationships