【作者】 王世民；

【导师】 杜晨霞； 吴养洁；

【作者基本信息】 郑州大学 ， 有机化学， 2012， 博士

【摘要】 双极分子主体材料由于自身结构特征已成为电致磷光器件最有潜力的主体材料之一。本论文采用氮杂芴作为骨架结构,设计合成了两系列具有优良双极传输性能的主体材料,并以这些主体材料为配体制备出了系列高效发光的一价铜配合物,考察了它们的光电性能。最后还合成了两个系列高效的红色锐带发光的3d-4f双金属异核配合物,在系统研究了它们的发光性能的基础上,制备出了性能优良的红色锐带OLED器件。1.合成了两个系列以4,5-二氮杂芴为骨架结构的新型双极主体材料,通过核磁质谱和元素分析对它们的结构进行了确认,对其中六个化合物进行了单晶结构分析。通过电化学分析和量子化学模拟计算,得到了化合物的HOMO、LUMO轨道能级和带隙。结果表明：该系列化合物表现出明显的双极传输性能,通过引入不同空穴传输基团来调控化合物的载流子传输能力和HOMO和LUMO轨道能级,使主体材料与磷光客体材料能级更匹配。与传统的主体材料CBP相比,这些化合物有较CBP更高的三线态能级,和更为合适的HOMO和LUMO轨道能级。以绿色磷光配合物Ir(ppy)3为主体材料,通过制备有机电致发光器件考察了此类双极主体材料性能,结果表明：这两个系列的化合物是性能优良的双极主体材料。其中,化合物DPAPAF、DCPAF和DCSBF作为主体材料的器件性能最为优秀,亮度分别达到了8246.2 cd/m2、1899.1 cd/m2和24123.0 cd/m2,电流效率分别为22.62 cd/A,14.93cd/A和40.83 cd/A。2.利用4,5’-二氮杂芴类化合物较强的配位能力,将这些双极性化合物作为配体与一价铜离子配位,结合含膦配体(PPh3,PEP)以及卤素配体(C1,Br,I),采用混配的方式制备了阳离子型和中性两个系列的一价铜配合物。通过元素分析,质谱对他们的结构进行了确认,并对其中七个配合物进行了单晶结构分析,结果表明：双齿氮杂配体和含膦配体与一价铜离子形成具有变形四面体构型的稳定的四配位阳离子；当有卤素离子参与配位时,卤素离子种类及反应条件对配合物的结构均有较大影响。对其光物理性能的系统研究表明：一价铜化合物发光属于的3MLCT的磷光发射,发光强度与发光谱带位置与化合物的聚集状态关系很大,配合物在固体状态和PMMA膜中发光较好,溶液中则发生严重的发光淬灭。分子的刚性增加可以减小配合物激发态的构型扭曲程度,增强了发光效率,一价铜离子形成类似“Y”形状时,激发态变形程度最小,发光效率较高。用PVK中掺杂旋涂的方法考察了五种离子型配合物的电致发光性能,发现掺杂Cu(DPAPAF)(PP)(BF4)和Cu(DPASBF)(PEP)(BF4)的器件电致发光性能较好。其中以Cu(DPASBF)(PEP)为客体材料的器件最大亮度达到了1614.80 cd/m2,其最大电流效率为6.11 cd/A,相应功率效率为1.37 lm/W。进一步说明DPAPAF和DPASBF配体都有很好的双极传输性能。3.利用席夫碱锌配合物作为第二配体,TTA, TFA作为第一配体,合成了两个系列的新型3d-4f异核双金属Zn(Ⅱ)-Eu(Ⅲ)配合物。通过元素分析对配合物结构进行了确认,并得到了化合物的Eu(TTA)2(TFA)(ZnS2)晶体结构。对系列化合物发光性能研究表明：这两个系列的化合物都显示了Eu3+离子的特征锐带发射,没有出现希席碱锌配体的发射峰,说明了席夫碱锌配体对Eu3+离子有较好的敏化作用。我们发现水杨醛系列配合物的发光量子效率明显比香草醛系列配合物的高,通过研究这些配合物的发光机理发现：配体到铕离子能量传递效率(Φη)的不同是造成这种差别的主要原因,香草醛席夫碱锌中性配体三线态能级较低以及可能存在的LMCT跃迁有可能造成能量回传,导致发光效率降低。以发光量子效率最高的配合物Eu(TTA)2(TFA)(ZnS2)为发光材料,制备了三层电致发光器件,该器件的最大亮度高达1982.5 cd/m2,最大电流效率为9.9 cd/A,相应的功率效率为5.2 lm/W,外量子效率为5.3%,是迄今报道的性能较好的红色锐带发光器件之一。更多还原

【Abstract】 The bipolar host material is one of the most potential host materials for electro-phosphorescent devices. In this thesis, two series of excellent bipolar host materials are designed and synthesized by utilizing 4,5-diazafluorene segment as the backbone structure. These bipolar host materials are also used as ligand for the synthesis of highly luminescent Cu(I) complexes. Their photo-and electro-luminescent properties are systematically studied. We also synthesize two series of sharp red emitting 3d-4f heterodimetallic complexes. The EL device with excellent performance was fabricated based on a heterodimetallic complex.1. Two series of bipolar host materials are designed and synthesized by utilizing 4,5-diazafluorene segment as backbone structure. The compounds are characterized by 1H NMR, MS and elemental analysis. Six single crystals of the compounds were determined by X-ray diffraction. HOMO/LUMO energy levels of the compounds were obtained through electrochemistry analysis and modeling theory. The results indicated that:these kinds of compounds exhibit apparent bipolar properties. The HOMO/LUMO energy levels and carrier transporting ability can be modified by introducing electron-donating moieties into the molecule. Compared with traditional host material CBP, the above compounds have higher triplet energy levels (ET) and more suitable HOMO and LUMO energy levels. The above characteristics can be confirmed by doping Ir(ppy)3 into the host materials and investigating their EL performance. The results illustrated that these compounds are good bipolar host materials for electrophosphorescent devices. Among them, the devices base on DPAPAF, DCPAF and DCSBF as host material showed the excellent EL performance with the maximal luminance of 8246.2 cd/m2,1899.1 cd/m2 and 24123.0 cd/m2, and the current efficiencies of 22.62 cd/A,14.93cd/A and 40.83 cd/A, respectively.2. The bipolar host materials are used as ligand for synthesizing Cu(I) complexes owing to the strong coordination ability of 4,5-diazafluorene derivatives. By synergistic coordination of phosphine ligands, halide ion and host compounds with Cu(I), two kinds of Cu(I) complexes(one is neutral type, another is cationic type) have been synthesized. The complexes are characterized by 1H NMR, MS and elemental analysis. Seven single crystals of the complexes were determined by X-ray diffraction. In cationic type Cu(I) complexes, Cu(I) coordinates with two N atoms and two P atom, forming stable distorted tetrahedral geometry. However, halide ions and its reaction conditions influence the final structure markedly. Photophysical properties of the complexes are systematically studied. The results show that:the luminescence of the Cu(I) complexes are 3MLCT phosphorescent emission in nature. The luminescent properties depend profoundly on the state of Cu(I) complexes. In the solid state and PMMA film, Cu(I) complexes show much more efficient phosphorescence than in solution. Large rigid configurations of the complexes eliminate the possibility of flattening distortion in the excited states and finally enhance the luminescence efficiencies. The tri-coordinated Cu(I) complexes in the solid state exhibit intense photoluminescence because of the slightly distortion in the excited state. The EL properties of Cu(SBF)(PP)(BF4), Cu(DPAPAF)(PP)(BF4), CuI(SBF)(P), Cu(DPASBF)(PEP)(BF4) and Cu(DISBF)(PP)(BF4) are studied. Among the five complexes, Cu(DPASBF)(PEP)(BF4) and Cu(DPAPAF)(PP)(BF4) exhibited better EL properties. The EL device with Cu(DPASBF)(PEP)(BF4) as emitting dopant showed a maximum luminance of 1614.80 cd/m2, a maximum current efficiency of 6.11 cd/A, demonstrating excellent bipolar transporting properties of DPASBF and DPAPAF.3. Two series of d-f heterobimetallic complexes are synthesized by using Shiff base Zn(II) as second ligands and TTA and TFA as the first ligands. The single crystal of complex Eu(TTA)2(TFA)(ZnS2) is obtained and confirmed. The photophysical properties show that:the complex exhibits efficient red emissions typical of Eu3+ion and no emission bands from Shiff base Zn(II) are observed, suggesting that the energy transfer from the Shiff base Zn(II) to the Eu(III) centre is very efficient. We also found that the luminesce efficiency of the salicylaldehyde series complexes is higher than the vanallic series. The higher sensitization efficiency of the salicylaldehyde series complexes maybe the main resaon for this result. The lower triplet energy levels of the vanallic Shiff base Zn(II) ligand and the back energy transfer to the LMCT state may causing the lower luminesce efficiency of the vanallic series. The EL properties of complex Eu(TTA)2(TFA)(ZnS2), with the highest luminesce efficiency among the complexes, is studied. The triplet device base on Eu(TTA)2(TFA)(ZnS2) as emitting dopant showed a maximum luminance as high as 1982.5 cd/m2 and a maximum current efficiency of 9.9 cd/A, corresponding power efficiency of 5.2 lm/W and external quantum efficiency of 5.3%. This result ranks the complex Eu(TTA)2(TFA)(ZnS2) as one of the most efficient europium-based electroluminescent materials.更多还原