【摘要】 叙述了制备高纯度有机电致发光材料 8 羟基喹啉铝 (Alq3 )的方法 ;通过X射线衍射谱、核磁共振谱、红外吸收光谱、质谱、X射线光电子发射谱及荧光光谱测试分析 ,对Alq3 的结构和特性进行了表征。标定了Alq3中喹啉环的存在 ;分析了Alq3 中各个H原子的归属、Alq3 分子内部金属离子和配位体之间的相互作用以及该螯合物的分子构型。进一步证实Alq3 分子中Al—O键为共价键而非离子键。通过X射线衍射谱分析了样品的化学成分 ;由X射线光电子发射谱分析了Alq3 分子中的电子状态和晶体特性。得到了Alq3 的荷质比为45 9 1以及由于金属Al本身的特性 ,使得在Alq3 中Alq+ 2 继续裂解为Alq+ 的几率很小。证实了Alq3 的荧光发射光谱位于 5 10nm处 (绿光范围 ) ,光激发位于喹啉环上而不是金属铝离子。与镓、铟螯合物相比 ,Alq3 中铝离子成键共价性弱 ,极化力较强。更多还原

【Abstract】 An comprehensive understanding of the characteristics of the organic material tris-(8-hydroxyquinoline) aluminum (Alq 3) is meaningful for organic light-emitting devices (OLEDs). Thin films of Alq 3 are among the most efficient electroluminescent molecular films known to date. Alq 3 samples were synthesized and purified. The purity of samples is up to 98.5%. The electronic and crystallographic structure of Alq 3 has been studied. The results of a joint experimental investigation based on a combination of X-ray diffraction (XRD) spectrum, hydrogen nuclear magnetic resonance (NMR) spectrum, infrared absorption (IRA) spectrum, mass (MS) spectrum, X-ray emission (XRE) spectrum and fluorescence spectrum of Alq 3 have been investigated. The analysis on NMR spectrum of Alq 3 shows that the coordinate interaction between Al 3+ and O ion is more intensive than that between Al 3+ and N ion. Al 3+ hasn’t replaced H ion that suggests the Al-O bond is covalent but not ionic bond in Alq 3 molecule. There are still H + around O ion. Since there are six coordination bonds around Al 3+, O and N ions are both have strong binding force with Al 3+. Therefore Alq 3 has two types of geometrical isomers, namely mer isomer and fac isomer. From the IRA spectrum of the Alq 3, the broad characteristic peak at 3 417cm -1 corresponding to OH - stretching vibration confirmed that the Al-O are coordinate not ionic bond. The prominent peaks which is the characteristic of the absorption vibration of the aromatic ring skeleton at 1 588, 1 550, 1 467 and 1 400cm -1 suggests that the conjugate action of aromatic rings in molecule is very strong and all electron orbit of quinolinic rings are π bonding hybridizations. The disagreement between IRA spectrum of Alq 3 and HQ is excellent for indicating that there is a strong coordinate action which affect O bonding heavily between Al 3+ and O ions. From the MS spectrum the ratio of charge/mass of Alq 3 has been achieved. We prospect if a further cleavage occurred, a peaks of Alq + after losing a ligand from Alq + 2 should locate at m/e=171. However, the peak was not observed indicating that the state of Alq + is difficult to exist. The IRE data shows that the K α1,2 peaks have shifted comparing to Al due to the perturbation as the ligand gives to 2p electron of Al. The perturbation is related to coordination intensity. The shift of K β of Alq 3 mainly resulted from the chemical environment variation around Al atomics. It also relate to binding intensity and coordination number. The intensity of K β is lower than that of K α The wave length of K β is shorter than that of K α.The peak of K β shifted to lower energy (about 3.5eV) whereas the peak of K α1,2 shifted to higher energy (0.3 and 1.6eV) comparing to Al. Surprisingly, a weak adjoint peak at 1 537.5eV was observed. We ascribed it to the formation of the hybridization orbit among O 2s, O 2p, N 2s, N 2p and Al 3p orbits. Fluorescence data confirmed the existence of a fluorescent species formed between Al ion and 8-hydroxyquinolinol.更多还原