新型红光至近红外磷光铱配合物的合成、结构及性能研究

发布时间：2018-04-28 21:30

本文选题：红光至近红外磷光材料 + 铱配合物　；参考：《吉林大学》2017年博士论文

【摘要】：有机发光材料近些年来在显示、照明、传感、医疗和能源等领域扮演着越来越重要的角色。其中基于过渡金属络合物的有机磷光材料,由于其中心存在如铱、铂等重金属原子,可以通过强自旋轨道耦合(SOC)和快速系间窜越(ISC)将自身的三线态和单线态激子全部用于发光,将内量子效率提升至100%,从而引起了人们极大的兴趣。目前绿光、黄光有机磷光材料的效率及寿命已经基本能达到产业化的要求,但是高性能的红光至近红外磷光材料仍有待进一步的开发。金属铱配合物由于具有磷光寿命较短、发光效率高、合成提纯简单、光色易调节、良好的热学及电化学稳定性等优点,成为了设计新型高效红光至近红外磷光材料的一个研究热点。本论文设计合成了一系列含有脒胍基辅助配体的新型红光至近红外磷光铱配合物,对其晶体结构、热学性质、光物理性质、电化学性质、理论计算、载流子传输能力等性质进行了研究,并基于该系列铱配合物制备了红光至近红外磷光电致发光器件,讨论了该系列配合物中材料结构与性能之间的关系。1、在第二章中,以1-(4-氟苯基)异喹啉,1-(2,4-二氟苯基)异喹啉为第一配体,以脒基配体dipba(N,N′-diisopropylbenzamidinate)为辅助配体合成了两种新型的深红光磷光铱配合物SFPIQBA和DFPIQBA,并对这两个化合物各方面性质进行了表征。这种独特的C··N··Ir··N四元环配位结构显著改变了配合物的光电性能,与经典辅助配体乙酰丙酮相比,这类脒基辅助配体可以有效提升配合物HOMO能级并且降低能隙,有助于配合物实现深红光发射,理论计算表明这两个配合物的HOMO/LUMO轨道分布较为分离,预示其具有双载流子传输能力,并通过飞行时间法(time of flight)载流子测试进行了验证。两个化合物均具有良好的深红光发射(640 nm左右),较高的磷光量子产率和较短的磷光寿命。以SFPIQBA和DFPIQBA为发光客体制备的电致发光器件的最大外量子效率和最大功率效率分别为15.4%、9.3lm/W和16.7%、10.4 lm/W,CIE色坐标为(0.70,0.30)和(0.69,0.31),即使器件亮度达到了1000 cd/m2时,器件的外量子效率和功率效率仍保持10.6%、3.5 lm/W和10.8%、3.6 lm/W这一较高水平。2、在第三章中,以1-苯基异喹啉作为第一配体,脒基类配体dipba作为辅助配体合成了一种新型的深红光磷光铱配合物PIQBA。PIQBA具有铱配合物中少见的多晶相现象,分别为730 nm近红外发射的晶相A和680 nm深红光发射的晶相B。通过对不同晶相中分子间作用力、堆积结构、分子构型的分析,研究了两个晶相之间结构与性能的关系。脒基类辅助配体dipba中富电子的双N配位结构对铱配合物分子前线轨道构成产生了很大影响,理论计算表明PIQBA具有离域的电子云分布特性,TOF迁移率测试表明了其具有双载流子传输能力。热学性质表明PIQBA具有良好的热稳定性,有利于真空蒸镀器件的制备。以化合物PIQBA为发光客体的器件发射峰位为676 nm,最大外量子效率为10.7%,最大功率效率为1.9 lm/W,CIE色坐标为(0.71,0.28),器件的最大亮度达到5909 cd/m2。表现了非常好的红光色纯度及光谱稳定性。3、在第四章中,以7,8-苯并喹啉和1-苯基异喹啉衍生物为第一配体,使用胍基类辅助配体dipig(N,N′-diisoproguanidinate)合成了四种新型红光至近红外磷光铱配合物BZQPG、PIQPG、SFPIQPG、DFPIQPG。这系列化合物相比于之前讨论的含有脒基辅助配体的配合物有着更加红移的发射峰位、更短磷光寿命和更高的磷光量子产率。理论计算表明胍基辅助配体相比于脒基辅助配体给电子能力更强,更有助于提高配合物的HOMO能级,降低配合物能隙。并且与中心铱原子的配位能力也比脒基辅助配体更强,从而有效减少了分子振动能量损失。这四个化合物具有良好的热学及电化学稳定性,且拥有高效的双载流子传输能力。以它们做为发光客体制备的电致发光器件均表现稳定而高效的电致发光性能,以BZQPG、PIQPG、SFPIQPG和DFPIQPG为发光客体的器件最大外量子效率分别为27.3%、12.1%、16.3%和16.7%,电致发光波长分别为592 nm、684 nm、656 nm、652 nm。器件表现了良好的光谱稳定性和较小的效率滚降。4、在第五章中,通过在第一配体1-苯基异喹啉上进行简单的取代基修饰,配合脒胍基辅助配体合成了三种新型近红外磷光铱配合物MPIQBA、MPIQPG和CF3PIQPG,在不引入更大的共轭基团的情况下将配合物的发光波长延伸到了近红外区域,由于配合物中配体共轭程度的增加往往会引起分子聚集,导致发光淬灭,所以这种设计方式有助于获得高效率的近红外磷光材料。同时较小的分子量也有利于蒸镀型电致发光器件的制备。理论计算表明其HOMO/LUMO轨道分布在不同的基团上,TOF测试表明其具备双载流子传输能力,热学和电化学测试表明三个化合物均具有良好的热学和电化学稳定性。以它们作为磷光客体制备了电致发光器件,其中MPIQBA器件最大发射波长为688 nm,器件最大外量子效率为12.0%,CIE色坐标为(0.71,0.28);MPIQPG器件最大发射波长为692 nm,器件最大外量子效率达到了11.6%,CIE色坐标为(0.71,0.28);CF3PIQPG器件最大发射波长为692 nm,器件最大外量子效率达到了6.3%,CIE色坐标为(0.70,0.28),三个化合物器件的亮度都达到了1500 cd/m2以上。综上所述,我们合成了一系列新型红光至近红外磷光铱配合物,这系列铱配合物的创新点在于使用了新型的脒基和胍基辅助配体,与传统的乙酰丙酮类辅助配体相比,其富电子的双N配位结构能够有效稳定中心正三价的金属铱原子,同时与中心铱原子形成的四元配位环有着更强的刚性,这样可以减少分子中由于振动引起的非辐射能量损失,有助于配合物磷光量子产率的提高。理论计算表明,这种脒胍基辅助配体很大程度上参与了配合物的前线轨道构成,使铱配合物的HOMO和LUMO轨道分布产生分离,并可以显著提高配合物分子的HOMO能级,降低配合物能隙。载流子迁移率测试表明这系列铱配合物具有高效的双极性传输能力,可以有效减少电致发光器件中的三线态-三线态淬灭。以这系列配合物制备的器件也均表现出非常好的电致发光性能,我们通过研究这系列铱配合物中材料结构与性能的关系,为以后设计高性能的红光至近红外磷光铱配合物提供了新的思路。
[Abstract]:Organic light-emitting materials have been playing a more and more important role in the fields of display, lighting, sensing, medical and energy sources in recent years. Organic phosphors based on transition metal complexes, such as iridium, platinum and other heavy metal atoms, can make their three lines through strong spin channel coupling (SOC) and fast system channeling (ISC). The excitons of the state and single state are all used for luminescence, and the internal quantum efficiency is raised to 100%, which has aroused great interest. At present, the efficiency and life of the yellow light organic phosphor materials have basically reached the requirement of industrialization, but the high performance red to near infrared phosphors still need further development. Due to its short phosphor life, high luminescence efficiency, simple purification, easy adjustment of light and color, good thermal and electrochemical stability, it has become a research hotspot in the design of new high efficiency red to near infrared phosphor materials. A series of new red to near infrared phosphorus containing amidine guanidine assisted ligands was designed and synthesized in this paper. The crystal structure, the thermal properties, the photophysical properties, the electrochemical properties, the theoretical calculation, the carrier transmission capacity and the properties of the carrier transmission are studied. The relationship between the structure and properties of the materials in this series of complexes.1, at second, is discussed. In the chapter, 1- (4- fluoro phenyl) isoquinoline, 1- (2,4- two fluoro phenyl) isoquinoline as the first ligand, and the amid ligand dipba (N, N '-diisopropylbenzamidinate) as the auxiliary ligand, two new types of new dark red phosphorescent iridium complexes are synthesized, SFPIQBA and DFPIQBA, and the properties of the two compounds are characterized. This unique C. N. The N four membered ring coordination structure significantly changed the photoelectrical properties of the complexes. Compared with the classical auxiliary ligands, acetacetone, the amid based ligand could effectively improve the HOMO level of the complex and reduce the energy gap, and help the complex to achieve deep red emission. The theoretical calculation shows that the HOMO/LUMO orbital distribution of the two complexes is relatively separated. It indicates that it has dual carrier transmission capacity and is verified by the carrier test of time of flight (time of flight). All two compounds have good deep red light emission (about 640 nm), high phosphorescence quantum yield and short phosphor lifetime. The largest electroluminescent devices prepared with SFPIQBA and DFPIQBA as luminescent objects The external quantum efficiency and maximum power efficiency are 15.4%, 9.3lm/W and 16.7%, 10.4 lm/W, CIE color coordinates (0.70,0.30) and (0.69,0.31). Even if the device brightness reaches 1000 cd/m2, the external quantum efficiency and power efficiency of the device remain 10.6%, 3.5 lm/W and 10.8%, 3.6 lm/W in this high level.2. In the third chapter, the 1- phenyl isoquinoline is used. For the first ligand, the amid base class ligand dipba is used as the auxiliary ligand to synthesize a new type of deep red phosphorescent iridium complex PIQBA.PIQBA with rare polycrystalline phase in the iridium complex. The crystalline phase A of 730 nm near infrared emission and the crystalline phase B. emitted by the deep red light emission of 680 nm are stacked structures and molecules through the intermolecular interaction in the amorphous phase. The relationship between the structure and the properties between the two crystalline phases is studied. The double n coordination structure of the amitrid based auxiliary ligand dipba has a great influence on the formation of the molecular front-line orbit of the iridium complex. The theoretical calculation shows that the PIQBA has the distribution characteristics of the electron cloud in the field, and the TOF mobility test shows that it has a double carrier transmission. The thermal properties show that PIQBA has good thermal stability and is beneficial to the preparation of vacuum evaporating devices. The emission peak of the device with compound PIQBA as the luminescent object is 676 nm, the maximum external quantum efficiency is 10.7%, the maximum power efficiency is 1.9 lm/W, the CIE color coordinates are (0.71,0.28), and the maximum brightness of the device reaches 5909 cd/m2.. The normal red color purity and spectral stability.3, in the fourth chapter, using 7,8- benzoquinoline and 1- phenyl isoquinoline derivatives as the first ligand, using guanidine auxiliary ligand dipig (N, N '-diisoproguanidinate) to synthesize the new type of red light to near infrared phosphor iridium complex BZQPG, PIQPG, SFPIQPG, DFPIQPG., compared to the series of compounds. The previously discussed complexes with amidamidine assisted ligands have a more red shift emission peak, shorter phosphor lifetime and higher phosphorescent quantum yield. Theoretical calculations show that guanidine assisted ligands are more powerful than amidamidine assisted ligands, and are more helpful to improve the HOMO level of the complexes and to reduce the energy gap of the complexes. The coordination ability of iridium atoms is also stronger than amid assisted ligands, which effectively reduces the molecular vibration energy loss. These four compounds have good thermal and electrochemical stability and have high efficient double carrier transmission capacity. The electroluminescent devices, prepared by them as luminescent objects, show stable and efficient electroluminescence. The maximum external quantum efficiency of the devices with BZQPG, PIQPG, SFPIQPG and DFPIQPG as luminescent objects is 27.3%, 12.1%, 16.3% and 16.7% respectively, and the electroluminescent wavelengths are 592 nm, 684 nm, 656 nm, and 652 nm., showing a good spectral stability and a smaller efficiency rolling down.4 in the fifth chapter, through the first ligand 1- phenyl isoquinoline. Three novel near infrared phosphor iridium complexes, MPIQBA, MPIQPG and CF3PIQPG, are synthesized by simple substituent modification, and the luminescence wavelengths of the complexes are extended to the near infrared region without the introduction of a larger conjugate group. The increase of the ligand conjugation in the complexes often causes the molecules. Aggregation leads to light quenching, so this design helps to obtain high efficiency near infrared phosphor materials. At the same time the smaller molecular weight is beneficial to the preparation of electroluminescent electroluminescent devices. The theoretical calculation shows that the HOMO/LUMO orbit is distributed on different groups, and the TOF test shows that it has dual carrier transmission capacity, thermal and electrical properties. Chemical tests show that the three compounds have good thermal and electrochemical stability. Electroluminescent devices are prepared by them as phosphorescent objects. The maximum emission wavelength of MPIQBA devices is 688 nm, the maximum external quantum efficiency of the device is 12%, the CIE color coordinate is (0.71,0.28), the maximum emission wavelength of the MPIQPG device is 692 nm, and the maximum external device is the device. The quantum efficiency is 11.6%, the CIE color coordinate is (0.71,0.28), the maximum emission wavelength of the CF3PIQPG device is 692 nm, the maximum external quantum efficiency of the device reaches 6.3%, the CIE color coordinate is (0.70,0.28), and the brightness of the three compound devices is above 1500 cd/m2. In conclusion, we have synthesized a series of new red light to near infrared phosphorescent iridium. The innovation of this series of iridium complexes lies in the use of new amidinyl and guanidine assisted ligands. Compared with the traditional acetacetone auxiliary ligands, their electron rich double n-coordination structures can effectively stabilize the central positive trivalent metal iridium atom, and have a stronger rigidity in the four yuan coordination ring formed by the central iridium atom. In order to reduce the non radiation energy loss caused by the vibration in the molecule, it is helpful to improve the phosphor quantum yield of the complexes. The theoretical calculation shows that the amidamidine assisted ligands are largely involved in the front-line orbit of the complexes, separate the HOMO and LUMO orbital distribution of the iridium complexes, and can significantly improve the complex molecules. The HOMO energy level reduces the energy gap of the complex. The carrier mobility test shows that the series of iridium complexes have high efficient bipolar transmission ability and can effectively reduce the three wire state - three line state quenching in the electroluminescent devices. The relationship between the structure and properties of iridium complexes provides a new idea for the design of high performance red to near infrared phosphorescent iridium complexes.

【学位授予单位】：吉林大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O641.4

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