Metal Iridium Complexes And Its Application

Phosphorescent iridium complexes have attracted more and more attention due to their excellent photophysical and photochemical properties, such as high quantum efficiency, long life-time, easy to adjust the emission wavelength, etc.. They have been applied to biological imaging, chemical sensors, and optical function nanomaterials and so on. In this thesis, three types of iridium complexes were synthesized and were applied in phosphorescent cell marker, chemosensor for Cu²⁺ and nanomaterials. The details were shown as follows:1. PEG-modified water-soluble iridium complexes for cell markers Generally, PEG is a good water-soluble, biocompatible, fat-soluble, and widely applied in the fields of biochemistry. In this work, A water soluble iridium(III) complex was prepared by introducing PEG via click chemistry. The experiments showed that it had low cytotoxicity, good membrane permeability and exclusive staining in cytoplasm, which can be an excellent promising candidate for the design of new generation luminescent bioprobes.2. Cationic iridium complex and its application to chemosensor for Cu²⁺ The cationic iridium complex containing a number of coordination sites was synthesized. This complex has been shown to display extreme selectivity for Cu²⁺ over other metal ions. The signaling changes are observed through UV/Vis absorption, fluorescence emission. The ESI-MS analysis confirmed that the iridium complex was coordinated with Cu²⁺, leading to phosphorescence emission quenching. Therefore, it can be used as"turn-off"type phosphorescent chemical sensor for Cu²⁺.3. Iridium complex with pyridine groups to apply for phosphorescent nanomaterials A phosphorescent iridium complex containing pyridine groups was synthesized. The micro/nano cube structure were prepared by molecular self-assembly with benzene-1,3,5-tricarboxylic acid. The effect of different temperature, ratio, reaction time, pH value on the self-assembly process was investigated in details. The mechanism was discussed according to the crystal structure between the iridium complex and benzene-1,3,5-tricarboxylic acid. By the similar molecular self-assembly with benzene-1,3,5-tricarboxylic sodium salt, phosphorescent nanowires were also obtained.