Molecular Design,Synthesis And Photophysical Properties Of Phosphorescent Iridium Complexes Containing Nido-carborane

Phosphorescent iridium complexes are widely used in various optical functional applications due to their excellent photophysical properties.However,due to the lack of special and effective functional groups and novel coordination modes,there is still a single complex structure type,poor luminous performance and other issues,this paper designed the nested carborane groups as various new organic ligands and applied them to phosphorescent iridium complex systems with various coordination modes to synthesize a series of novel phosphorescent mononuclear and heteronuclear iridium complexes containing nido-carborane units were studied for their structure,excited state and photophysical properties.The specific research content of this paper is mainly divided into the following three parts:1.Synthesis,structure and properties of neutral phosphorescent iridium complexes based on nido-carborane negative divalent ligandIn this chapter,four novel neutral phosphorescent iridium complexes containing nido-carborane negative divalent ligands are designed and synthesized,in which the negative monovalent ligand is 2-phenylpyridine and the zero-valent ligand is 4,4-divalent Tert-Butyl-2,2-bipyridine.Then the structure is characterized and confirmed by means of nuclear magnetic,high-resolution mass spectrometry and X-ray single crystal diffraction,and the photophysical properties of such complexes are studied by ultraviolet absorption spectrum,phosphorescence emission spectrum,phosphorescence lifetime and electrochemical test.The results show that,except for the iridium complexes with nested carborane as backbone coordination,they do not emit light,the other complexes all exhibit effective orange light emission,and the final DFT quantitative calculations indicate the triplet excited state characteristics?T₁?It mainly originates from the charge transfer transition?LLCT?of the negative divalent ligand containing nido-carborane to the zero-valent ligand.2.Synthesis,structure and properties of red neutral phosphorescent iridium complex based on nido-carborane negative monovalent ligandIn this chapter,four novel neutral phosphorescent iridium complexes containing nido-carborane phosphorous-sulfide negative monovalent ligands are designed and synthesized.The negative bivalent ligand is biphenyl,and the zero-valent ligand is bipyridine or o-phenanthroline.Porphyrin,then characterize and confirm its structure by means of nuclear magnetic,mass spectrometry and X-ray single crystal diffraction,etc.,and study the photophysical properties of such complexes by ultraviolet absorption spectrum,phosphorescence emission spectrum,phosphorescence lifetime and electrochemical test.The research results show that there are two sets of isomers among the four complexes,and all of them show red light emission.The quantitative calculation results show that the triplet excited state characteristics?T₁?of these complexes are mainly derived from negative divalent The charge transfer transition from ligand to zero-valent ligand?LLCT?is partly derived from the charge transfer transition from metal iridium to zero-valent ligand and negative monovalent ligand?MLCT?.3.Synthesis,structure and properties of red binuclear iridium-copper complex based on nido-carborane diphosphorus ligandThis chapter designs and synthesizes a new neutral binuclear iridium-copper complex containing nido-carborane diphosphorus ligands,and also synthesizes a new cationic dinuclear iridium copper complex containing phenyl diphosphorus ligand Comparison of photophysical properties,and then characterize and confirm its structure by means of nuclear magnetic,mass spectrometry and X-ray single crystal diffraction,etc.The photophysical properties of such complexes were studied by ultraviolet absorption spectrum,phosphorescence emission spectrum and phosphorescence lifetime.The research results show that the neutral binuclear iridium-copper complex containing nested carborane diphosphorus ligands shows obvious deep red light emission.The final quantitative calculation results show that the T₁ excited state characteristics of the complex mainly come from metals The charge transfer?MLCT?transition from the copper center to the bridged ligand is partly derived from the charge transfer?LLCT?transition from the nido-carborane double phosphorus ligand to the bridged ligand and the nested carborane double phosphorus ligand The transition to metal iridium?LMCT?.