氟取代三(8-羟基喹啉)铝衍生物电子结构、电子光谱的量子化学研究: 实现蓝色发光的途径

采用Gaussian 03程序包和密度泛函理论(DFT)B3LYP/6-31G方法, 研究了三(8-羟基喹啉)铝(Alq3)的3种氟代衍生物的电子结构与电子光谱, 讨论了氟原子在不同位置取代对Alq3的前线轨道、HOMO-LUMO能隙以及电子光谱的影响, 发现氟取代使Alq3的前线轨道能级降低, 在6位碳上氟代的Alq3的HOMO-LUMO能隙变大, 吸收和发射光谱发生蓝移, 而在5和7位碳上氟代的Alq3能隙变小, 吸收和发射光谱发生红移. 理论模拟结果与实验事实基本吻合, 证明在Alq3分子的合适位置进行化学修饰可实现蓝色发光.

Quantum Chemical Investigation for Electronic Structure and Spectrum of F-substituted Alq3 Derivatives: An Approach to Blue Luminescence of Alq3 Derivatives

The ground state and electronic spectra in F-substituted Alq_3 derivatives \,an important electroluminescent material,are studied by using density functional theory(DFT) B3LYP/6-31G in programme Gaussian 03.The effect of substituted position in Alq_3 on their energies,HOMO-LUMO gap and the electronic spectrum are discussed.It is found that F-substitutions in Alq_3 resulted in the decrease of both HOMO and LUMO energies,and the degree of such decrease in energy of HOMO and LUMO levels is dependent on the F-substituted position.Significantly,the HOMO-LUMO bandgap of 6-FAlq_3 is found to be increased,as a result,its absorption and emission spectra are greatly blueshifted.The results obtained from the theoretical investigation was in agreement with the experimental ones, providing an approach to obtain the important blue luminescence Alq_3 derivatives.