Syntheses, Structure And Properties Of Luminescent Cu(Ⅰ) Coordination Complexes Based On Nitrogen-containing Heterocyclic Ligands

Phosphorescent complexes have gained increasing interest for their applications on organic light emitting devices (OLEDs), light-emitting field-effect transistor (LEFEC) and light-emitting electrochemical cells (LECs), as they offer a new path to obtain high quantum efficiency devices which can make use of both singlet and triplet excitations. With the growing interest in the highly efficient organic light-emitting diodes, employing cheap and nontoxic Cu(Ⅰ) complexes as electrophosphorescent materials is becoming attractive. In this thesis, a series of Cu(Ⅰ) coordination complexes have been synthesized by using novel diazafluorene ligands and phosphine ligands which serve as second ligands. The structures of the new compounds have been determined by single-crystal X-ray diffraction, X-ray powder diffraction, elemental analysis and IR measurement. And their optical band gaps, thermal stabilities and luminescent properties have also been investigated. The relationship between the structures and properties of the series of Cu(Ⅰ) coordination compounds have been studied. The main content and results achieved in this thesis are summarized as follows:1. The background and recent progress for the luminescent materials, Cu(Ⅰ) coordination complexes and complexes based on4,5-diazafluorene have been outlined. The disadvantages of the current research have been pointed out. The research aim and route of this thesis have been presented.2. Syntheses, structures and luminescent properties of the new Cu(Ⅰ) coordination complexes built upon the diazafluorene ligands and phosphine ligands. A series of five diazafluorene ligands have been designed and synthesized. By the assembly of Cu(CH3CN)4PF6with diazafluorene ligands and phosphine ligand as second ligands, eight new Cu(Ⅰ) complexes ([Cu(DF)(TPP)2PF6](1),[Cu(DF)[TPP(o-CH3)](CH3CN)PF6](2),[Cu(ACE)(TPP(P))PF6]2(DDF)(3),[Cu(DF)(DPEphos)PF6](4),[Cu(dedaf)(TPP)2PF6](5),[Cu(2,7-dibr-DF)(TPP)2PF6](6),[Cu(3,8-dibr-Phen)(TPP)2PF6](7) and [Cu(2,7-dibr-DF)(TPP(o-CH3))(CHCl3)PF6](8) have been synthesized. The structures of all complexes have been determined by single-crystal X-ray diffraction. The Cu(Ⅰ) atoms show distorted tetrahedral coordination environment. In compound2,3and8, solvent molecules coordinate to the copper(Ⅰ) atoms. Besides2,3and8, the other complexes exihibit as the Cu[(N-N)(P-P)]+coordination type. Their photophysical and spectroscopic properties were studied. The optical band gaps of the compounds show that they can be classified as semiconductors. The emission of all the compounds may derive from the metal-ligand charge transfer(MLCT).3. Synthesis, structures and properties of luminescent Cu(I) halide complexes built upon pyridine ligands and phosphine ligands. Three Cu(I) halide complexes based on pyridine ligands and phosphine ligands,[(CuI)2(CH3CN)2[TPP(m-CH3)]2](9),[(CuI)2(pyridine)2[TPP(m-CH3)]2](10), and [(CuI)2(bipy)2[TPP(m-CH3)]2](11), have been synthesized and structurally characterized. All of the complexes showed excellent luminescent properties. The emission of the compounds may derive from the metal-ligand charge transfer (MLCT) as well as the halide-ligand charge transfer (XLCT).