【作者】 朱东霞；

【导师】 苏忠民； 王悦；

【作者基本信息】 东北师范大学 ， 无机化学， 2005， 博士

【摘要】 近年来,西佛碱金属配合物的合成、结构和催化性能等被广泛研究。水杨醛类双西佛碱金属配合物具有较大共轭体系的四齿含氮配体,被期望是一类很好的发光化合物,但此类配体及其配合物的发光性能的相关报道却很少,我们对此类化合物的发光性能进行了系统的研究。西佛碱及其配合物的单晶培养较难,迄今以合成及表征工作居多,X-衍射晶体结构数据偏少。分析材料的单晶结构来考察材料固体分子堆积状态,进而确定影响固体分子具有良好的载流子传输能力的关键因素,将对设计合成具有好的载流子传输能力的有机电致发光材料是有很强的指导意义的。通过设计配体 π 共轭体系的大小、共轭大 π 键的共平面性及其刚性程度和分子母体上取代基的种类等可以调控金属配合物分子发光的频率和强度等发光特性,为进一步设计和研制发光性能更好的金属配合物奠定基础,从而探索研制能在传感器技术、光化学和电致发光器件等方面具有应用前景的金属配合物。本文利用两个系列六个水杨醛类双西佛碱配体和乙酸锌反应,合成出两个系列六个水杨醛类双西佛碱锌的配合物。发现它们室温下无论在溶液中还是在固体膜状态下均具有较强的荧光发射。通过六个配合物荧光量子效率计算,表明不同取代基对双水杨醛双西佛碱金属配合物的荧光效率有着不同影响。配合物中供电子取代基使双西佛碱金属配合物的荧光效率增强,吸电子取代基使双西佛碱金属配合物的荧光效率降低。这类有机金属配合物的发光主要是由于配体与配体之间的 π~*→π 跃迁产生的(LLCT),配合物的锌中心对增强配体的 π~*→π 跃迁的荧光发射起重要作用。以此六个配合物为基础制备作为发光材料用在电致发光器件。通过简单双层结构和三层结构分别讨论了它们在电致发光器件中的应用。研究表明配合物[N,N′-(2-羟基苯次甲基)环已二胺根]合锌可以用于电致发光白光器件的制备。在我们现有的材料和实验条件下,我们所制备的利用 exciplex 发光的白光器件取得了较好的结果。虽然从色度、效率和亮度等方面的性能同现有文献报道的结果相比并不是最好的,但它的发光机理不同于普通的多层或掺杂结构,具有结构简单、重复性好、色度稳定等优点,并且已证明这种方法制备的器件,其性能仍有进一步提高的潜力,所以它将是制备有机白光器件的一条有效途径。对合成的两个系列六个西佛碱-吡啶金属锌配合物进行单晶培养,得到了其中四个配合物的单晶结构。经单晶 X 射线衍射分析,均显示为五配位的扭曲四方锥型构型。这些配合物固体分子堆积状态中都存在着不同形式的分子间相互作用,它们室温下无论在溶液还是在固体状态下均具有很强的荧光性质。这类配合物属于典型的配体-配体电荷转移型(LLCT)发光配合物。虽然中心金属锌对前线分子轨道贡献较小,但是它对提高整个分子刚性却起到了非常重要的作用,可以做为电荷转移的桥梁。因此这些新的发光金属配合物,在制造有机电致发光器件方面可能有潜在的应用价值。有机电致发光器件的电致发光效率决定于基态与激发态间的电子跃迁机理。我们使用量子化学 TD-DFT/6-31G(d)方法对以上两类十二个配合物基态前线分子轨道性质及其第一单重激发态的发光性质进行了理论研究。计算得到的这些配合物的最大电子吸收光谱值与实验测得的最大吸收峰值吻合很好,理论计算的结果具可靠性。从理论上解释了此两类配合物的电子光谱产生红移的原因。配合物的电子光谱来源于配体-配体电荷转移。更多还原

【Abstract】 Recently, Schiff base complexes have attracted much attention with their synthesis,structure and calalyze properties. Bis(salicyladimine) complexes are also good tridentateN-donating ligands with large π-conjugating system, they should be good luminescentcompounds. However, little reports on the luminecent properties of these ligands and theircomplexes hase been found, we are very interested in the luminescent properties of thesecompounds. There are difficult to gain the crystal of Schiff base and Schiff base complexes.Now little reports on the crystal of these ligands and their complexes hase beenfound .Through the analysis of crystal structure to illustrate the state in the molecular andconfirm the key factor that effect the charge transport properties of the molecular in solid, it isvery important for the design and synthesis of organic electroluminescent materials with goodcharge transport properties. The change of the size of π-conjugated system of the ligand and the electronic effect ofsubstituents on the ligand are important factors for modulating its luminescent properties. Thefrequency and intensity of the luminescence of the complex are modulated via the design ofthe ligand-modified and center metal, so that luminescent properties are improved based onmetal coordination compounds. Six Bis(salicyladimine) complexes were synthesized. The complexes have luminescenceat room temperature in solution and the solid state. Their fluorescence property has beenstudied and their fluorescence quantum yields have been determined. It is illuminated thatdifferent substituents have different effect on fluorescence quantum yields. Electron-donatingsubstituents improve the fluoresunce quantum yields of Schiff base complexes, whileelectron-withdrawing substituents descend the fluorescence quantum yields of Schiff basecomplexes. It is found that the fluorescent emission of these complexes originates fromligand-centered π-π* transition. The Zn (Ⅱ) centers play a key role in enhancing thefluorescent emission of the ligands. Through the simple double or three layer strurcture, we study the organicelectroluminescent properties of these complexes. We fabricated organic white light-emittingdevices (LEDs) based on the exciplex emission formed at the interface between thehole-transporting layer NPB and the emitting layer and electron-transportinglayer(1,2–cyclohexanediamino-N, N’- bis (salicylidene) zinc. The devices have goodperformance with simple structure and pure colour. The method will be a effect way tofabricatorganic white light-emitting devices (LEDs). Six bis(salicyladimine) –pyridine complexes were synthesized. Four crystal structure ofthese complexes were determined. The complexes are five-coordinated, distorted squarepyramid. There are different molecular interactions in the solid state of these complexes.Complexes have strongly fluorescent emission both in solution and in the solid state at roomtemperature. The fluorescent emission of these complexes originates from ligand-centeredπ-π* transition. The Zn (Ⅱ) centers play a key role in enhancing the fluorescent emission ofthe ligands.Their luminescent properties show that they are a new class of luminescent metalcomplexes with potential applications in OEL devices. The efficiency of organic light-emitting devices were determined by the mechanism of theelectron transition between the ground and excited state. On the basis of the optimizedgeometrical structure, the electronic spectrum properties of the twelve complexes werestudied by time-dependent density functional theory (TD-DFT) via a hybrid functional ofB3LYP and 6-31G(d) basis set. The molecular orbital, electron transition and the character ofthe electronic spectrum were studied. The TD-DFT calculation result is in good agreementwith the experimental values and gives the reason of red-shift in the electronic spectrum.更多还原