Phosphorescent Iridium(?) Complexes:Design,Synthesis And Applications In Light-Emitting Devices And Photodynamic Therapy

Organic phosphorescent materials can ultilize both singlet and triplet excitons.Hence,their internal quantum efficiency can reach 100%theoretically when used in light-emitting devices,and the lifetime is longer in comparision with that of fluorescent material.It has attracted great interest because of their wide applications in phosphorescent organic light-emitting diodes,chemical sensing and bioimaging,etc.As we know,phosphorescent transition metal complexes have a number of excellent photophysical properties,such as long emission lifetime,large Stokes shift,low photobleaching,easily tunable emission wavelength and high quantum efficiency.They have great potential in the applications of light-emitting devices and bioimaging technology.There are mainly two strategies for regulating the photophysical properties of the complexes,which contacts modification of the ligands skeleton and synthesis of the new ligands.Now,a series of novel organic phosphorescent Ir???complexes were synthesized and used in luminescent devices and bioimaging fields.This paper mainly includes two parts:1.Design and synthesis of the chlorine-functionalized blue iridium???complexes for phosphorescent organic light-emitting devicesFour highly efficient blue heteroleptic iridium???complexes were designed and synthesized.The change of the ancillary ligand can not only regulate the energy gap but also increase the?_PLL and narrow the FWHMs.The materials exhibited good solubility in organic solvents with the excellent chemical stabilities and showed bright pure blue emissions.Owing to the performance of the blue phosphors,solution-processed blue organic light-emitting diodes have been successfully fabricated.The EL peak,CIE coordination and FWHM of the device based on Ir4 are all superior to the device based on FIrpic.2.Design and synthesis of anthraquinone functionalized iridium???complexes for photodynamic therapyThe commercial photosensitizers often exhibit weak absorption and poor stability,and their singlet oxygen generation efficiency is relatively low.We aim to explore new materials to solve these problems.Anthraquinone functionalized Ir1-Ir4 complexes were designed and synthesized for photodynamic therapy.Among them,Ir1 showed high singlet oxygen generation efficiency in both solution and living cells.In addition,Ir1 showed specific staining of mitochondria and the costaining coefficient is up to 95.4%.Finally,excellent photodynamic therapy performance was achieved using Ir1 as the photosensitizer.